JP2012066546A - Method of producing fusion material of thermoplastic liquid crystal polymer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a fusion material of a thermoplastic liquid crystal polymer film fused by using ultrasonic waves.SOLUTION: The method includes: a step of laminating a thermoplastic liquid polymer film and an adherend with the thermoplastic liquid crystal polymer up and with the adherend down; and a step of obtaining the fusion material of the thermoplastic liquid crystal polymer film by fusing the thermoplastic liquid crystal polymer film and the adherend by using the ultrasonic waves while bringing the ultrasonic horn of an ultrasonic wave fusion apparatus into direct contact with the upper side of the thermoplastic liquid crystal polymer film.

Description

  The present invention relates to a thermoplastic liquid crystal obtained by fusing a film made of a thermoplastic polymer capable of forming an optically anisotropic melt phase (hereinafter referred to as a thermoplastic liquid crystal polymer film) using ultrasonic waves. The present invention relates to a method for producing a polymer film fusion product.

  In recent years, there has been remarkable progress in technology in the field of microelectronics, and the demand for miniaturization and weight reduction of portable electronic devices such as mobile communication has become stronger, and the expectation for high-density mounting has further increased. As materials suitable for high-density mounting, heat-resistant resins such as polyimide, polyether ether ketone, polyether sulfone, polyphenylene ether, and polyphenylene oxide have attracted attention.

  A film made of such a heat-resistant resin is laminated with a metal foil such as a copper foil and used for a printed wiring board. Since heat processing is difficult with such a heat-resistant resin, an adhesive such as an epoxy-based adhesive is usually selected and used for adhesion between films made of the heat-resistant resin. However, when films are bonded together using a foreign material such as an epoxy adhesive, the original ability of the film may not be exhibited due to the presence of the foreign material.

  Therefore, in recent years, thermoplastic liquid crystal polymer films capable of thermal bonding have attracted attention in this field. Thermoplastic liquid crystal polymer films can be bonded to each other without using an adhesive. Therefore, the original capabilities of thermoplastic liquid crystal polymer films are excellent low moisture absorption, low gas permeability, high frequency characteristics and A laminate or a fused film can be provided without impairing chemical resistance.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2001-88219), a thermoplastic liquid crystal polymer film and an adherend are overlapped, and then heat treatment is performed between rolls in a state where both are sandwiched between non-adhesive adherends. A method for producing the laminate is disclosed, wherein the laminate is separated from the non-adhesive adherend while being crimped.

  More specifically, this document describes a state in which a thermoplastic liquid crystal polymer film is sandwiched between non-adhesive adherends, rolls are disposed above and below, and a roll-shaped ultrasonic horn is used as an upper pressure roll. It is described that a heating roll is used as the lower pressure roll.

JP 2001-88219 A

  However, in the manufacturing method described in Patent Document 1, since films are laminated using a pressure roll while heat-treating between the rolls, it is difficult to perform local fusion at an arbitrary position. Moreover, since the fusing speed is also affected by the winding speed of the roll, it is difficult to control the fusing speed.

  In addition, thermoplastic liquid crystal polymers have higher heat resistance compared to thermoplastic films such as vinyl chloride and polypropylene, which are commonly used for ultrasonic fusion, so when liquid crystal polymer films are ultrasonically fused, However, the conventional ultrasonic fusion method has a problem that the fusion strength is low.

Accordingly, an object of the present invention is to provide a method for producing a thermoplastic liquid crystal polymer film fusion product, which can perform local fusion at an arbitrary position and can easily control the fusion rate. It is in.
Another object of the present invention is to provide a method for producing a thermoplastic liquid crystal polymer film fusion product that not only improves the adhesive strength but also has an excellent appearance of the fusion product.

Still another object of the present invention is to provide a method for producing a thermoplastic liquid crystal polymer film fusion product that can be used not only manually but also easily using a machine.
Another object of the present invention is to provide a method for producing a thermoplastic liquid crystal polymer film fusion product that is not only highly cycleable but also can be produced at low cost.

  The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, (1) the molecules constituting the liquid crystal polymer have no entanglement between molecules and are excellent in vibration absorption. As a result of finding out that the cause of the difficulty in ultrasonic fusion is that the frictional heat due to the vibration is not sufficiently generated even when ultrasonic waves are applied. In order to achieve ultrasonic fusion of the liquid crystal polymer film, it was found that the liquid crystal polymer film can efficiently absorb vibration during ultrasonic fusion by bringing the ultrasonic horn into direct contact with the liquid crystal polymer film. It was.

  Subsequently, (3) in order to prevent the thermoplastic liquid crystal polymer from being melted at once due to the efficiently absorbed energy, it is important to lay an elastic mat as a film cradle, whereby the liquid crystal polymer film The inventors have found that the vibration of the ultrasonic wave applied to can be controlled, and that a good appearance and sufficient adhesive strength can be imparted to the melt of the liquid crystal polymer film, and the present invention has been completed.

That is, the present invention is a method for producing a fusion product of a film made of a thermoplastic polymer capable of forming an optically anisotropic melt phase (hereinafter referred to as a thermoplastic liquid crystal polymer film),
A step of superposing a thermoplastic liquid crystal polymer film and an adherend thereof (for example, a thermoplastic liquid crystal polymer film) on an elastic mat with the thermoplastic liquid crystal polymer film on an adherend and a laminate;
An ultrasonic horn of an ultrasonic fusing machine is brought into direct contact with the thermoplastic liquid crystal polymer film, and the thermoplastic liquid crystal polymer film and the adherend are fused ultrasonically to melt the thermoplastic liquid crystal polymer film. Obtaining a kimono.

For example, the pressure of the ultrasonic horn against the thermoplastic liquid crystal polymer film may be about 40 to 100 kg / cm ² . Further, the vibration amplitude of the ultrasonic horn may be about 40 to 60 μm. Further, the output of the ultrasonic oscillator may be about 200 to 450 W. Such ultrasonic fusion is usually performed by point movement or line movement of an ultrasonic horn.

  The elastic mat is preferably composed of a heat-resistant elastic mat. Further, the elastic modulus of the elastic mat may be about 4 to 40 MPa, and the thickness thereof may be about 0.5 to 10 mm.

  Moreover, this invention also includes the thermoplastic liquid crystal polymer film melt | fusion material obtained by the said manufacturing method. Such a fused product may be, for example, a thermoplastic liquid crystal polymer film having a length in the MD direction of 1000 m or more.

  In the production method of the present invention, by using ultrasonic waves without using a pressure roll and a non-adhesive adherend, local fusion can be performed at an arbitrary position of the thermoplastic liquid crystal polymer film. The fusion speed can be easily controlled.

  Moreover, the adhesive strength of the thermoplastic liquid crystal polymer film fusion product can be improved by applying an ultrasonic horn at a specific pressure. In particular, when the adherend is a thermoplastic liquid crystal polymer film, welding can be performed at a level close to the strength of the base material.

  Furthermore, since the irregularities on the surface of the thermoplastic liquid crystal polymer film fusion product can be reduced, the appearance of the fusion product is improved.

Furthermore, by adjusting the vibration amplitude and / or output of the ultrasonic wave, not only can manual fusion be performed, but also automation using a machine can be easily accommodated.
Furthermore, when the elastic mat has heat resistance, contamination of the fusion-bonded material by the elastic mat can be prevented even if the adherend side is heated to a high temperature. Further, when the elastic mat has a specific elastic modulus and / or thickness, it is possible to efficiently control the ultrasonic vibration to the thermoplastic liquid crystal polymer film.

  Furthermore, the production method of the present invention not only has high cycleability for producing a fused product, but also does not require the use of a pressure roll, so that the production equipment can be made inexpensive.

  Furthermore, since the production method of the present invention does not require a foreign substance such as an adhesive, it can not only produce a thermoplastic liquid crystal polymer film fusion product at a low cost, but also exhibits the original properties of the thermoplastic liquid crystal polymer film. be able to.

It is the schematic for demonstrating the manufacturing method of the ultrasonic fusion material of the thermoplastic liquid crystal polymer film which concerns on one Embodiment of this invention. (A) is a schematic sectional drawing which shows an example of the front-end | tip shape of the ultrasonic horn used with the manufacturing method which concerns on one Embodiment of this invention, (b) is the schematic side view. In the manufacturing method which concerns on one Embodiment of this invention, it is the schematic for demonstrating the fusion | melting method using an XY stage.

  The method for producing an ultrasonic fusion product according to the present invention is a method in which a thermoplastic liquid crystal polymer film is fused using ultrasonic waves. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining one embodiment of a method for producing an ultrasonic fused product of the present invention.

  As shown in FIG. 1, the thermoplastic liquid crystal polymer film 2 and the adherend 2 ′ are disposed on the elastic mat 7 in a state where the thermoplastic liquid crystal polymer film is overlaid on each other. The ultrasonic horn 3 is disposed so as to be in direct contact with the thermoplastic liquid crystal polymer film 2 existing on the side opposite to the elastic mat 7 at a desired adhesion site between the thermoplastic liquid crystal polymer film 2 and the adherend 2 ′. The

  On the other hand, the ultrasonic fusion machine includes at least an ultrasonic oscillator 6, a vibration element 4 connected to the ultrasonic oscillator 6, and an ultrasonic horn 3 attached to the vibration element 4. Further, the vibration element 4 is attached to the electric slider 5, and the vibration element 4 and the ultrasonic horn 3 are linearly moved according to the electric slider 5.

  When performing ultrasonic fusion, first, an electric signal is oscillated in the ultrasonic oscillator 6, and the electric signal is transmitted to the vibration element 4. Next, the electrical signal transmitted in the vibration element 4 is converted into mechanical ultrasonic vibration energy, and the ultrasonic vibration energy is transmitted to the ultrasonic horn 3. Then, this mechanical vibration energy becomes ultrasonic vibration having a predetermined vibration amplitude in the ultrasonic horn 3 and is given to an adhesion portion between the thermoplastic liquid crystal polymer film 2 and the adherend 2 '.

  Then, frictional heat is generated at the bonding portion to which ultrasonic vibration is applied, and the thermoplastic liquid crystal polymer film 2 and the adherend 2 'are melted and bonded at the bonding portion by the frictional heat. In the embodiment of FIG. 1, the vibration element 4 and the ultrasonic horn 3 attached to the electric slider 5 are linearly moved with respect to the thermoplastic liquid crystal polymer film 2 and its adherend 2 ′ in a stationary state, and the thermoplastic liquid crystal. The polymer film 2 and its adherend 2 ′ are fused.

(Thermoplastic liquid crystal polymer film)
The thermoplastic liquid crystal polymer film is formed from a liquid crystalline polymer that can be melt-molded. The thermoplastic liquid crystal polymer is not particularly limited as long as it has a chemical structure as long as it is a liquid crystalline polymer that can be melt-molded. , Thermoplastic liquid crystal polyester, or thermoplastic liquid crystal polyester amide having an amide bond introduced therein.

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

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

(1) Aromatic or aliphatic dihydroxy compounds (see Table 1 for typical examples)

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

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

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

  Representative examples of the liquid crystal polymer obtained from these raw material compounds include copolymers having the structural units shown in Tables 5 and 6.

  Of these copolymers, a polymer containing at least p-hydroxybenzoic acid and / or 6-hydroxy-2-naphthoic acid as a repeating unit is preferable, and in particular, (i) p-hydroxybenzoic acid and 6-hydroxyoxy- A polymer containing a repeating unit with 2-naphthoic acid, (ii) at least one aromatic hydroxycarboxylic acid selected from the group consisting of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 4,4 ′ A repeating unit of at least one aromatic diol selected from the group consisting of dihydroxybiphenyl and hydroquinone and at least one aromatic dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid Polymers containing are preferred.

  For example, in the polymer (i), when the thermoplastic liquid crystal polymer contains at least repeating units of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, the repeating unit (A) of p-hydroxybenzoic acid is used. And the molar ratio (A) / (B) of the repeating unit (B) to 6-hydroxy-2-naphthoic acid is (A) / (B) = about 10/90 to 90/10 in the liquid crystal polymer. Desirably, it is desirable that (A) / (B) = about 50/50 to 85/15, and more preferably (A) / (B) = 60/40 to 80/20. It may be a degree.

  In the case of the polymer (ii), at least one aromatic hydroxycarboxylic acid (C) selected from the group consisting of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 4,4′-dihydroxy At least one aromatic diol (D) selected from the group consisting of biphenyl and hydroquinone, and at least one aromatic dicarboxylic acid (E) selected from the group consisting of terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid. The molar ratio of each repeating unit in the liquid crystal polymer is about aromatic hydroxycarboxylic acid (C): aromatic diol (D): aromatic dicarboxylic acid (E) = about 30-80: 35-10: 35-10. More preferably, (C) :( D) :( E) = 35 to 75: 32.5 to 12.5: 3 May be about .5～12.5, more preferably, (C) :( D) :( E) = 40~70: it may be about 30 to 15: 30-15.

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

  The optical anisotropy at the time of melting referred to in the present invention can be recognized by, for example, placing a sample on a hot stage, heating and heating in a nitrogen atmosphere, and observing the transmitted light of the sample.

  As the thermoplastic liquid crystal polymer, for the purpose of obtaining the desired heat resistance and processability of the film, for example, the melting point (hereinafter referred to as Mp) is in the range of about 200 to about 400 ° C., particularly about 250 to about 350 ° C. However, from the viewpoint of film production, those having a relatively low melting point (for example, in the range of about 200 to about 300 ° C.) are preferable. Mp is determined by measuring the temperature at which the main endothermic peak appears with a differential scanning calorimeter (Shimadzu Corporation DSC).

  In addition, when higher heat resistance and melting | fusing point are required, it can raise even to desired heat resistance and melting | fusing point by heat-processing the film once obtained. If an example of the conditions of heat processing is demonstrated, even if the melting | fusing point of the film obtained once is 283 degreeC, if it heats at 260 degreeC for 5 hours, melting | fusing point will be 320 degreeC.

  The thermoplastic liquid crystal polymer may include a thermoplastic polymer such as polyethylene terephthalate, modified polyethylene terephthalate, polyolefin, polycarbonate, polyarylate, polyamide, polyphenylene sulfide, polyester ether ketone, and fluororesin within a range not impairing the effects of the present invention. It may be added.

  The thermoplastic liquid crystal polymer film used in the present invention is obtained by extrusion molding of a thermoplastic liquid crystal polymer. Any extrusion molding method can be applied as long as the direction of the rigid rod-like molecules of the thermoplastic liquid crystal polymer can be controlled, but the known T-die method, laminate stretching method, inflation method and the like are industrially advantageous. In particular, in the inflation method and the laminate stretching method, stress is applied not only in the mechanical axis direction of the film (hereinafter abbreviated as MD direction) but also in the direction orthogonal to this (hereinafter abbreviated as TD direction). Since a film having a balance between mechanical properties and thermal properties in the TD direction can be obtained, it can be used more suitably.

  In extrusion molding, it is preferable to involve a stretching process in order to control the orientation. For example, in extrusion molding by the T-die method, the melt sheet extruded from the T-die is not only in the MD direction of the film but also in the TD direction. You may extend | stretch simultaneously with respect to both, or you may extend | stretch the melt sheet extruded from T-die once in MD direction, and then extend in TD direction.

  The thermoplastic liquid crystal polymer film preferably has a molecular orientation SOR of 1.3 or less. Since the liquid crystal polymer film has a good balance of mechanical properties and thermal properties between the MD direction and the TD direction, it is more practical.

  Here, the molecular orientation degree SOR (Segment Orientation Ratio) refers to an index that gives the degree of molecular orientation, and is a value that takes into account the thickness of an object, unlike the conventional MOR (Molecular Orientation Ratio). This molecular orientation degree SOR is calculated as follows.

First, in a known microwave molecular orientation measuring instrument, a thermoplastic liquid crystal polymer film is inserted into a microwave resonant waveguide so that the film surface is perpendicular to the traveling direction of the microwave, and the film is transmitted. The electric field strength (microwave transmission strength) of the microwave is measured. And based on this measured value, m value (it calls a refractive index) is computed by following Formula.
m = (Zo / Δz) X [1-νmax / νo]
Where Zo is a device constant, Δz is the average thickness of the object, νmax is the frequency that gives the maximum microwave transmission intensity when the microwave frequency is changed, and νo is the average thickness of zero (that is, the object is Is the frequency that gives the maximum microwave transmission intensity.

Next, when the rotation angle of the object with respect to the vibration direction of the microwave is 0 °, that is, the vibration direction of the microwave and the direction in which the molecules of the object are best oriented, the minimum microwave transmission intensity is given. m ₀ to m value when the direction meets the rotation angle of the m value at 90 ° as _{m 90,} orientation ratio SOR is calculated by m ₀ / m _90.

  The degree of molecular orientation SOR required is naturally different depending on the field of application of the thermoplastic liquid crystal polymer film of the present invention, but when SOR ≧ 1.5, the orientation of the liquid crystal polymer molecules is significantly biased, so that the orientation is easily split. . In the case of an application field that requires shape stability such as no warping during heating, it is desirable that SOR ≦ 1.3. In particular, it is desirable that SOR ≦ 1.03 in the field of application where it is necessary to almost eliminate warping during heating.

  The thermoplastic liquid crystal polymer film used in the present invention may have any thickness, and includes, for example, a plate or sheet having a thickness of 5 mm or less. From the viewpoint of effectively using ultrasonic vibration, the thickness of the thermoplastic liquid crystal polymer film is preferably 500 μm or less, and more preferably in the range of 10 to 250 μm.

Further, as the thermoplastic liquid crystal polymer film, the thermoplastic liquid crystal polymer only needs to be included as a main material. Besides the above-described thermoplastic liquid crystal polymer film, the thermoplastic liquid crystal polymer and other electrically insulating materials (for example, Composite film with aluminum oxide, ceramic powder, etc., multiple types of thermoplastic liquid crystal polymer blend film, thermoplastic film (for example, polyarylate, polyetherketone, polyamide, polyethersulfone, polyetherimide, polyimide, polycarbonate, Polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene chloride, etc.) or polymer alloy films can be used. That.
In addition, additives, such as a lubricant and an antioxidant, may be blended in the raw material film as necessary.

(Adherent)
In the present invention, other adherends that can be laminated with the above-mentioned thermoplastic liquid crystal polymer film include various metal foils (copper, gold, silver, nickel, aluminum, etc.); thermoplastic resins or thermosetting resin films (preferably Thermoplastic liquid crystal polymer film, polyethylene terephthalate film, film made of ethylene-vinyl acetate copolymer, film made of ethylene-vinyl alcohol copolymer, thermoplastic film such as polyolefin film typified by polyethylene film) Can be mentioned. Of these adherends, a thermoplastic liquid crystal polymer film is preferred from the viewpoint of improving the strength of the fused product.

  The thickness of the adherend can be appropriately set according to the type and application of the adherend, and can be selected from a wide range of about 1 μm to 5 mm, for example. The thickness of the adherend is, for example, 5 mm or less. It may be 1 mm or less, more preferably 500 μm or less, and more preferably in the range of 10 to 250 μm.

  When the adherend is a thermoplastic liquid crystal polymer film, the thermoplastic liquid crystal polymer film and the thermoplastic liquid crystal polymer film as the adherend may be overlapped and fused with each other, Alternatively, in one thermoplastic liquid crystal polymer film, one end and the other end may be fused.

(Ultrasonic fusion machine)
The ultrasonic fusion machine used in the present invention converts an ultrasonic oscillator that supplies an electric signal for generating ultrasonic vibrations, and an electric signal supplied from the ultrasonic oscillator into ultrasonic vibration energy. A vibration element and at least an ultrasonic horn that applies ultrasonic vibration energy transmitted from the vibration element to the bonding site as ultrasonic vibration are provided.

  The ultrasonic horn itself can also amplify the vibration amplitude, but if necessary, a booster capable of amplifying the vibration amplitude may be provided between the vibration element and the ultrasonic horn. Good. When the ultrasonic vibration from the ultrasonic horn is transmitted to the thermoplastic liquid crystal polymer film, the adhesive portion of the thermoplastic liquid crystal polymer film and the adherend are fused.

  The shape of the ultrasonic horn to be fused may be various shapes such as a cylindrical horn, a prismatic horn, a conical horn, and a pyramid horn, and among these, a horn with a small tip is preferable.

  FIG. 2 is a schematic diagram for explaining a preferable tip shape of the ultrasonic horn. This ultrasonic horn has a prismatic shape whose tip is rounded into a scallop shape, and its front surface corresponds to the curved part of the scallop. As shown in FIG. 2, the front surface of the ultrasonic horn has a lateral width 8 and a radius of curvature R of the tip portion, and the side surface of the ultrasonic horn has a depth 9.

  For example, in the prismatic shape as shown in FIG. 2, the lateral width 8 of the ultrasonic horn may be about 10 mm to 100 mm, and the depth 9 may be about 1 to 100 mm. Moreover, in the shape (for example, cylindrical shape etc.) whose horizontal width of a front and the depth of a side surface are comparable, horizontal width 8 and depth 9 may be about 10 mm-100 mm.

  The tip of the ultrasonic horn preferably has a curved shape from the viewpoint of bringing the ultrasonic horn and the thermoplastic liquid crystal polymer film into contact with each other for fusion. For example, the curvature radius R is about 90% to 180% of the lateral width 8; More preferably, it is 100 to 160%.

  Note that the vibration element and the ultrasonic horn may be moved linearly using an electric slider or the like, or may be moved manually by a point. In the fusion process according to an embodiment of the present invention, since ultrasonic vibration can be efficiently transmitted to the liquid crystal polymer film, only the joining portion between the film and the adherend is heated and fused, and the liquid crystal polymer film and the ultrasonic horn Since no heat is generated at the close contact portion, the safety of manual fusion work can be improved.

  Moreover, continuous fusion | bonding is also attained by moving an ultrasonic transducer | vibrator and an ultrasonic horn with an electric slider. Further, since the speed can be easily adjusted, the shape after ultrasonic fusion is improved and uniform adhesive strength is obtained.

  The amplitude of the ultrasonic vibration transmitted directly from the ultrasonic horn to the thermoplastic liquid crystal polymer film is not particularly limited as long as the liquid crystal polymer film can be melted. However, from the viewpoint of quick adhesion, for example, the amplitude of the ultrasonic vibration is 20 μm. It may be about ˜80 μm, and preferably about 40 μm to 60 μm. If the ultrasonic vibration amplitude is too low, the adhesive force may be insufficient, and if the ultrasonic vibration amplitude is too high, a hole may be formed in the thermoplastic liquid crystal polymer film.

The ultrasonic frequency is not particularly limited, but is usually preferably 15 to 35 KHz, and particularly preferably 15 to 30 KHz.
The fusion time by ultrasonic vibration can be appropriately set according to other conditions such as amplitude, but may be, for example, about 0.05 seconds to 2.0 seconds, more preferably 0.1 seconds to It may be about 1.0 second.

Since ultrasonic vibration can be efficiently transmitted to the liquid crystal polymer film, the ultrasonic oscillation output may be, for example, about 200 to 450 W, and preferably about 250 to 400 W.
Further, the pressure applied to the tip of the ultrasonic horn may be, for example, about 40 to 100 kg / cm ² , and preferably about 45 to 90 kg / cm ² .

  FIG. 3 is a schematic diagram for explaining a state in which planar bonding is performed by repeating the linear movement of the ultrasonic transducer and the ultrasonic horn using the XY stage. The thermoplastic liquid crystal polymer film 2 and its adherend 2 ′ are overlapped, and an ultrasonic horn (not shown) is in contact with the thermoplastic liquid crystal polymer film 2. In this figure, the contact portion between the ultrasonic horn and the thermoplastic liquid crystal polymer film 2 is conceptually illustrated as 3 '. As shown in this figure, the ultrasonic horn is linearly moved in the direction of the arrow using an XY stage, and a large area is fused in a planar shape by repeating adhesion by the line movement.

(Elastic mat)
In the present invention, an elastic mat is used as an underlay for the thermoplastic liquid crystal polymer and its adherend in order to control vibration energy applied to the thermoplastic liquid crystal polymer film during ultrasonic fusion. In the present invention, heat can be generated mainly on the adhesive surface of the film, so that a wide variety of materials can be used as the elastic mat.

  For example, as materials of the elastic mat, polyvinyl chloride, polyurethane, natural rubber, synthetic rubber (IR, BR, SBR, CR, NBR, IIR, EPM, EPDM, fluorine rubber, silicone rubber, etc.), thermoplastic elastomer, etc. Can be mentioned. Among these, an elastic mat having heat resistance (for example, a mat formed of fluorine rubber, silicone rubber, or the like) is preferably used from the viewpoint of being able to cope with frictional heat conducted to the outside.

  The tensile modulus of elasticity of the elastic mat may be, for example, about 4 to 40 MPa, and preferably about 6 to 30 MPa. The elastic modulus is a value measured based on JIS K 7181.

  Further, the thickness of the elastic mat can be appropriately set according to the elastic modulus of the elastic mat, but the thickness of the elastic mat is, for example, about 0.5 mm to 10 mm from the viewpoint of appropriately releasing the temperature at the time of fusion. It may be 1 mm to 5 mm. If it is too thick, the amount of vibration absorption becomes large and ultrasonic fusion may not be possible. Conversely, if it is thin, vibration absorption is insufficient and the thermoplastic polymer film may be melted.

(Fused material)
In the present invention, a fused product obtained by fusing a thermoplastic liquid crystal polymer film and an adherend thereof can be obtained. The shape can be appropriately selected according to the bonding site, such as a bag shape or a sheet shape. Particularly, when the adherend is a thermoplastic liquid crystal polymer film of the same kind, a roll of the thermoplastic liquid crystal polymer film. The thermoplastic liquid crystal polymer film can be elongated (for example, the length in the MD direction: 1000 m or more). For example, in such a long liquid crystal polymer film, not only the appearance of the joint portion of the film is good, but also the strength at the joint portion of the film can be made a level close to the strength of the base material.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all by this Example. In the following examples and comparative examples, various physical properties were measured by the following methods.

[Thickness]
Using a digital thickness meter (manufactured by Mitutoyo Corporation), the obtained film was measured at 1 cm intervals in the TD direction, and an average value of 10 points arbitrarily selected from the center and the end was taken as the film thickness.

[Melting point]
The film was obtained by observing the thermal behavior of the film using a differential scanning calorimeter. In other words, the sample film was heated at a rate of 20 ° C./min to be completely melted, and then the melt was rapidly cooled to 50 ° C. at a rate of 50 ° C./min, and again raised at a rate of 20 ° C./min. The position of the endothermic peak that appeared when the film was recorded was recorded as the melting point of the film.

[Molecular orientation (SOR)]
In a microwave molecular orientation measuring machine, a liquid crystal polymer film is inserted into a microwave resonant waveguide so that the film surface is perpendicular to the traveling direction of the microwave, and the electric field strength of the microwave transmitted through the film (Microwave transmission intensity) is measured.

And based on this measured value, m value (it calls a refractive index) is computed by following Formula.
m = (Zo / Δz) X [1-νmax / νo]

  Where Zo is a device constant, Δz is the average thickness of the object, νmax is the frequency that gives the maximum microwave transmission intensity when the microwave frequency is changed, and νo is zero when the average thickness is zero (that is, the object is Is the frequency that gives the maximum microwave transmission intensity.

Next, when the rotation angle of the object with respect to the vibration direction of the microwave is 0 °, that is, the vibration direction of the microwave and the direction in which the molecules of the object are best oriented, the minimum microwave transmission intensity is given. m ₀ to m value when the direction meets the rotation angle of the m value at 90 ° as _{m 90,} orientation ratio SOR is calculated by m ₀ / m _90.

[Adhesive strength]
A peel test piece having a width of 1.5 cm is prepared from a laminate of a thermoplastic liquid crystal polymer film and an adherend, and the film layer is fixed to a flat plate with a double-sided adhesive tape. According to JIS C 5016, by a 180 ° method, The strength was measured when the adherend was peeled off at a speed of 50 mm / min.

[Tensile strength]
Measurement according to ASTM D882 was performed, and the average value of 5 points in the longitudinal direction (MD) was taken as the measured value.

[Visual inspection]
Using an optical microscope (5 times magnification) on the fused surface, the surface irregularities and the state of hole opening were confirmed, and the presence or absence of holes was confirmed.

(Reference Example 1)
A thermoplastic liquid crystal polymer having a melting point of 283 ° C. is melt-extruded with a copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (molar ratio: 73/27), and a film thickness of 25 is obtained by an inflation molding method. A liquid crystal polymer film 1 having a molecular orientation SOR of 1.03 was obtained. The liquid crystal polymer film 1 was subjected to heat treatment in a heat treatment furnace at Tm1-10 ° C. for 2 hours and at a melting point Tm1 + 10 ° C. for 3 hours to obtain a liquid crystal polymer film 2 having a melting point Tm2 (325 ° C.).

(Examples 1-4)
The thermoplastic liquid crystal polymer film 2 (thickness: 25 μm, 50 μm, 100 μm, 175 μm) obtained in Reference Example 1 is overlaid with the same thermoplastic liquid crystal polymer film 2 as an adherend, and a silicone rubber mat ( (Tensile elastic modulus: 10 MPa, thickness: 2 mm). Next, using an ultrasonic fusion machine (manufactured by Suzuki Marine Co., Ltd., ultrasonic oscillator “SUW-150”, ultrasonic horn: depth 4 mm × width 10 mm, curvature radius R: 10 mm), the oscillation frequency of the oscillation source: An ultrasonic fusion treatment was performed by directly applying an ultrasonic horn from above the thermoplastic liquid crystal polymer film 2 at 28 KHz, amplitude: 60 μm, adhesion time: 0.1 second, and pressure 50 kg / cm. Table 7 shows the evaluation results of the obtained laminate.

(Comparative Example 1)
The thermoplastic liquid crystal polymer film 2 (thickness: 50 μm) obtained in Reference Example 1 is overlaid with the same thermoplastic liquid crystal polymer film 2 as an adherend, and these films are sandwiched between non-adhesive adherends. It is. Subsequently, ultrasonic fusion treatment was performed in the same manner as in Example 1 except that an ultrasonic horn was applied from above the non-adhesive adherend. Table 7 shows the evaluation results of the obtained laminate.

(Comparative Example 2)
The thermoplastic liquid crystal polymer film 2 (thickness: 50 μm) obtained in Reference Example 1 is overlaid with the same thermoplastic liquid crystal polymer film 2 as an adherend, and these films are heated by a hot plate press. Bonding (thermal bonding conditions: 300 ° C., pressure: 40 kg / cm ² ) was performed. Table 7 shows the evaluation results of the obtained laminate.

(Comparative Example 3)
The thermoplastic liquid crystal polymer film 2 (thickness: 50 μm) obtained in Reference Example 1 is overlaid with the same thermoplastic liquid crystal polymer film 2 as an adherend, and these films are heated by a hot plate press. Bonding was performed (thermal bonding conditions: 330 ° C., pressure: 40 kg / cm ² ). Table 7 shows the evaluation results of the obtained laminate.

  As shown in Table 7, the melted thermoplastic liquid crystal polymer films of Examples 1 to 4 have various strengths and high strength and good appearance.

  On the other hand, in Comparative Example 1, since the liquid crystal polymer film was sandwiched between the non-adhesive adherends and ultrasonic waves were applied to the non-adhesive adherends as conventionally performed, the liquid crystal polymer films were excellent. Can not be fused.

  Also in Comparative Example 2, the adhesion between the thermoplastic liquid crystal polymer films is not good. Further, in Comparative Example 3 in which the temperature of the hot plate press was increased, although the adhesive strength of the fused portion was high, there were irregularities on the surface of the fused portion.

  In the method for producing a thermoplastic liquid crystal polymer film fusion product of the present invention, for example, a thermoplastic liquid crystal polymer film fusion product that can be used as a transmission line material for electrical and electronic products can be produced efficiently and simply. . Moreover, if this manufacturing method is used, the elongated thermoplastic liquid crystal polymer film can be obtained.

  As described above, the preferred embodiments of the present invention have been described. However, various additions, modifications, or deletions are possible without departing from the spirit of the present invention, and such modifications are also included in the scope of the present invention. It is.

2 ... thermoplastic liquid crystal polymer film 2 '... adherend 3 ... ultrasonic horn 3' ... contact part 4 of ultrasonic horn ... vibration element 5 ... electric slider 6 ... ultrasonic oscillator 7 ... elastic mat 8 ... width 9 ... Depth

Claims (10)

A method for producing a fused product of a film made of a thermoplastic polymer capable of forming an optically anisotropic melt phase (hereinafter referred to as a thermoplastic liquid crystal polymer film),
A process of superposing the thermoplastic liquid crystal polymer film and the adherend on the elastic mat with the thermoplastic liquid crystal polymer film on the adherend and down;
An ultrasonic horn of an ultrasonic fusing machine is brought into direct contact with the thermoplastic liquid crystal polymer film, and the thermoplastic liquid crystal polymer film and the adherend are fused ultrasonically to melt the thermoplastic liquid crystal polymer film. Obtaining a kimono;
A method for producing a thermoplastic liquid crystal polymer film fusion product comprising: The manufacturing method according to claim 1, wherein the pressure of the tip of the ultrasonic horn with respect to the thermoplastic liquid crystal polymer film is 40 to 100 kg / cm ² .   3. The manufacturing method according to claim 1, wherein the vibration amplitude of the ultrasonic horn is 40 μm to 60 μm.   The manufacturing method according to claim 1, wherein the adherend is a thermoplastic liquid crystal polymer film.   The manufacturing method according to claim 1, wherein the output of the ultrasonic oscillator is 200 to 450 W.   The manufacturing method according to claim 1, wherein the elastic mat is a heat-resistant elastic mat.   The method according to any one of claims 1 to 6, wherein the elastic mat has an elastic modulus of 4 to 40 MPa and / or a thickness of 0.5 to 10 mm.   The manufacturing method according to claim 1, wherein the ultrasonic fusion is performed by point movement or line movement of the ultrasonic horn.   A thermoplastic liquid crystal polymer film fusion product obtained by the production method according to claim 1.   The thermoplastic liquid crystal polymer film fusion product according to claim 9, having a length in the MD direction of 1000 m or more.

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