JP4205512B2 - Fluorine-based laminated film - Google Patents

Description

  The present invention relates to a fluorine-based laminated film that is formed by laminating a film made of a fluororesin on at least one surface of a polyester film, can be produced by extrusion lamination, and has heat resistance necessary for printed wiring board production.

  Conventionally, a laminated film in which a film made of a fluororesin is laminated on at least one surface of a stretched polyester film is known (for example, Patent Document 1).

  In general, the fluororesin laminated film including the laminated film is produced by a dry laminating method. However, in the dry laminating method, foreign matters are easily mixed between the film layers, and not only the flatness of the film is impaired, but also the appearance of the film is impaired due to the foreign matters and voids generated around the foreign matters. In addition, the surface of the fluorine film to be dry-laminated must be pretreated by corona treatment or the like, and the process is troublesome. Therefore, the present inventors have invented a laminated film that can be produced by extrusion lamination by using a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer (THV) resin (Japanese Patent Application No. 2002-51910). issue).

  However, the laminated film has insufficient heat resistance depending on the application, and improvement has been desired. For example, it is a release film use for printed wiring board manufacture. The release film is formed by stacking a plurality of glass cloth impregnated with an epoxy resin and then stacking a laminate of copper foils on a printed board by integrating the laminate with a press plate. Is placed between the laminate and the press plate. When the laminated film is softened by the heat and pressure of the press, the thickness becomes non-uniform, resulting in unevenness on the surface of the printed board to be formed or distortion of the board.

Japanese Patent Laid-Open No. 2002-067241 (Claims)

Accordingly, an object of the present invention is to provide a film that can be produced by an extrusion laminating method and that has a predetermined heat resistance.

That is, the present invention is the following film.
A THV mixed resin film containing tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymers THV1 and THV2 each having the following terpolymerization ratio is laminated on at least one surface of the stretched polyethylene terephthalate film. Film Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride 3 having a terpolymerization ratio of 40-70 wt% / 10-30 wt% / 10-30 wt% tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride 3 Terpolymer resin (THV1) and tetrafluoroethylene / tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymerization ratio of 30-50 wt% / 10-30 wt% / 30-50 wt% Hexafluoropropylene-vinylidene fluoride terpolymer resin (THV2 ).
The preferable aspect of said film is the following.
A film characterized in that THV1 is contained in an amount of 5% by weight or more of the weight of the THV mixed resin.
A film obtained by further laminating a film made of a fluororesin different from the THV mixed resin on the THV mixed resin film.
The film characterized in that the dissimilar fluororesin is a tetrafluoroethylene-ethylene copolymer resin or a tetrafluoroethylene-hexafluoropropylene copolymer resin.
10cm length from any position on the film surface, with a terminal thickness of 5mm, and the difference (R) between the maximum and minimum measured thickness is 5μm or less. Film.
The stretched polyethylene terephthalate film has a thickness of 5 to 1000 μm, and the THV mixed resin film has a thickness of 2 to 10 μm.
The film made of a different kind of fluororesin is a tetrafluoroethylene-hexafluoropropylene copolymer resin film having a thickness of 2 to 10 μm.
A film having a total film thickness of 10 to 300 μm.
A film obtained by further laminating a polyethylene film, a polypropylene film, or a polyester film on the film made of the different kind of fluororesin.
Moreover, this invention relates also to the coating film carrier film which consists of said film, and the film for mold release which consists of said film.
Furthermore, this invention is the following manufacturing method.
On at least one side of the stretched polyethylene terephthalate film,
Tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymer having a terpolymerization ratio of 40-70 wt% / 10-30 wt% / 10-30 wt% Polymer resin (THV1) and tetrafluoroethylene / hexafluorofluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymerization ratio of 30-50 wt% / 10-30 wt% / 30-50 wt% Propylene-vinylidene fluoride terpolymer resin (THV2)
A method for producing a laminated film comprising laminating a THV mixed resin containing the laminate by an extrusion laminating method.
A preferred embodiment of the above method is as follows.
A method wherein THV1 is contained in an amount of 5% by weight or more of the weight of the THV mixed resin.
A method comprising laminating a fluororesin different from the THV mixed resin on at least one surface of a stretched polyethylene terephthalate film by co-extrusion with the THV mixed resin by an extrusion laminating method.

  The film of the present invention can be made by extrusion lamination and has heat resistance. The heat resistance can be adjusted by appropriately changing the mixing ratio of the two types of THV resins.

  Various known stretched films can be used as the polyethylene terephthalate (PET) film in the present invention. Among these, biaxially stretched polyethylene terephthalate is preferable from the viewpoint of thickness accuracy, thermal characteristics, mechanical characteristics, price, and the like.

  The thickness of the PET film is 5 to 300 μm, preferably 25 to 100 μm. If it is thinner than the lower limit, the handleability is poor. On the other hand, if the thickness is larger than the upper limit, the film thickness accuracy is deteriorated, which is not preferable for carrier film applications requiring high thickness accuracy. Further, when the thickness is increased, there are problems such as an increase in manufacturing cost and an increase in waste.

The laminated film of the present invention uses a mixed resin of two kinds of THV resins each having a predetermined terpolymerization ratio. The two types of THV resins have a tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymerization ratio (hereinafter referred to as “ternary copolymerization ratio”) of 40 to 70% by weight / 10 to 30% by weight / 10. Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin (THV1) of ˜30 wt%, preferably 45-65 wt% / 15-25 wt% / 15-25 wt%, and Tetrafluoroethylene-hexa having an original copolymerization ratio of 30-50 wt% / 10-30 wt% / 30-50 wt%, preferably 35-45 wt% / 15-25 wt% / 35-45 wt% Fluoropropylene-vinylidene fluoride terpolymer resin (THV2). The crystallization temperature of THV1 is about 120 to 170 ° C., and the crystallization temperature of THV2 is about 80 to 120 ° C. Thus, by combining two kinds of THV resins having different thermal characteristics, the heat resistance of the film can be improved while maintaining the adhesion to PET. In the present invention, the crystallization temperature is a value measured by heating at a temperature of 10 ° C./min by putting a sample of about 10 mg to 100 mg in an aluminum pan by DSC and referring to an empty pan.

The mixing ratio of THV1 and THV2 can be appropriately set according to the application, production conditions, and the like. For a product requiring heat resistance, such as a release film, THV1 is 5% by weight or more, preferably 20% by weight or more, and most preferably 30% by weight based on the weight of the mixed resin. On the other hand, if THV1 exceeds 95% by weight, the adhesion between PET and the THV mixed resin may be insufficient.

  Further, by using a mixed resin of THV1 and THV2, it is possible to widen the allowable range of the lamination conditions, for example, the resin temperature at the time of lamination.

  When THV1 and THV2 are mixed, the mixing can be performed by a commonly used mixing method. For example, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, or various kneaders are used.

The thickness of the THV mixed resin layer is preferably 2 to 10 μm, more preferably 2 to 5 μm. If the thickness is less than the lower limit, there may be a portion where the THV layer is missing due to thickness variation, resulting in poor peeling performance. The resin film may not be sufficiently bonded. On the other hand, if the thickness is larger than the upper limit, various performances are not improved for the increased manufacturing cost.

  Examples of the fluororesin different from the tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin (hereinafter referred to as “THV”) used in the present invention include, for example, polytetrafluoroethylene (PTFE), tetrafluoro Ethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (CTFE), polyfluorinated Examples include vinylidene (PVdF). Preferably, ETFE and FEP are used. The heterogeneous fluororesin includes a THV resin having a copolymerization ratio different from the copolymerization ratio of the entire THV mixed resin. As such a THV resin, a THV1 resin is preferable. The thickness of the dissimilar fluororesin film is preferably 2 to 10 μm, more preferably 3 to 5 μm. If the thickness is less than the lower limit, there may be a portion in which the dissimilar fluororesin film layer is missing due to variations in the film thickness, which may result in poor peeling performance. On the other hand, when it is thicker than the upper limit, the manufacturing cost increases.

  When the film of the present invention is used as a carrier film, the total thickness is preferably 10 to 300 μm, and particularly preferably 60 to 300 μm from the viewpoint of thickness accuracy.

  The film of the present invention can be made by extrusion lamination. The case where a three-layer film is produced will be described with reference to FIG. 1. A THV mixed resin film 1 and a fluororesin film 2 different from the THV mixed resin are coextruded from a T die at a temperature of 315 ° C., for example. Then, the resin composition film 1 side is pressure-bonded onto the stretched polyester film 3 between the nip roll 5 and the cooling roll 6, and the laminated film 4 of the present invention is wound up. This extrusion laminating method is superior to dry laminating in that a pretreatment such as a corona treatment of a fluororesin film is unnecessary and a step of drying an adhesive that usually requires a long time is unnecessary. Note that an adhesive such as an acrylic-modified, isocyanate-based, polyethyleneimine-based, polyurethane-based, or silane coupling agent may be applied to the polyester film surface in advance. Furthermore, when dry laminating a thin film, in order to ensure handling, the thin film is coextruded with a polyolefin resin or the like, or attached to a transfer film and collected, and the thin fluororesin is collected. After the film is dry-laminated on the polyester film, the coextruded polyolefin resin or the transfer film is peeled off. By coextruding with the THV mixed resin of the present invention, such a troublesome process is performed. Is no longer necessary.

  Preferably, a protective film layer made of polyethylene or the like is further provided on the THV mixed resin film or a fluororesin film different from the THV mixed resin, that is, on the surface opposite to the polyester film. If the protective film is peeled off and used immediately before placing the carrier film on the metal plate, it is possible to prevent the adhesion of dust and to form the cast film with higher thickness accuracy. The protective film may be any film as long as it adheres to the fluororesin layer. Examples thereof include films of various polyethylene, polypropylene, polyester, polyvinyl chloride, triacetyl cellulose, cellophane, polyamide, polycarbonate, aromatic polyamide, polyimide, polyetherimide, polyphenylene sulfide, polysulfone, polyethersulfone and the like. Of these, a high-density polyethylene film is preferable because of its low price. The thickness of the protective film is preferably 10 to 50 μm. The protective film can be laminated on the fluororesin layer by thermocompression bonding.

     Hereinafter, the present invention will be described in more detail by way of examples.

Film used Biaxially stretched polyethylene terephthalate film (PET): manufactured by Mitsubishi Chemical Polyester.
Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin:
THV1: THV500 (trade name), manufactured by Dyneon, 60% by weight of tetrafluoroethylene, 20% by weight of hexafluoropropylene, 20% by weight of vinylidene fluoride, crystallization temperature of 153 ° C.
THV2: THV220 (trade name), manufactured by Dyneon, tetrafluoroethylene 40% by weight, hexafluoropropylene 20% by weight, vinylidene fluoride 40% by weight, crystallization temperature 98 ° C.
Tetrafluoroethylene-ethylene copolymer (ETFE): Tefzel (trademark) 290, manufactured by Asahi Glass Co., Ltd.
Tetrafluoroethylene-hexafluoropropylene copolymer (FEP): 140J (trade name), manufactured by Mitsui DuPont Fluorochemical Co., Ltd.
Prepreg: Made of Mitsubishi Gas Chemical, glass epoxy.

Evaluation method (1) Measurement of flatness
With FILM THICKNESS TESTER KG601A (manufactured by Anritsu), measure the continuous thickness over a length of 10 cm in the machine direction of the film with a terminal diameter of 5 mm and determine the difference between the maximum and minimum Measure at 10 points every 1 cm perpendicular to the machine direction, and measure the thickness at 10 points every 1 cm along the machine direction of the film over a length of 10 cm perpendicular to the machine direction of the film. The average value was calculated, and R was 5 μm or less as A, and B exceeding 5 μm as B.
(2) The appearance of each film of foreign matter having a diameter of 300 μm or more was visually observed. The case where bubbles or foreign matters having a diameter of 300 μm or more were observed was designated as B, and the case where no bubbles were observed was designated as A.
(3) Heat resistance evaluation A printed circuit board having blind through-hole openings is sequentially laminated in a predetermined order via a prepreg, and each laminated film is arranged above and below the set of printed boards. A set of printed circuit boards sandwiched between the laminated films was heated and pressed (170 ° C., 490 N / cm ² ) with a press plate having a mirror finish, and the prepreg was integrated. After 60 minutes, the press pressure was released, the printed circuit board was taken out, the surface of the printed circuit board was visually observed, and A was found to have no irregularities, and B was recognized.

Film Preparation A film having each constitution shown in Table 1 was prepared. The mixing of THV1 and THV2 was performed with a twin screw extruder.
An acrylic modified adhesive is applied in advance while co-extruding a THV resin film from a T-die at a die temperature of 200 ° C. by an extruder and a fluororesin film different from the THV mixed resin in Examples 2 to 4. Laminated on one side of PET film. The temperature of the resin during lamination was about 150 ° C. The films of Comparative Examples 1 and 2 were prepared by a dry lamination method. Each evaluation was performed about the prepared film. The results are shown in Table 1.

 Since the film of the present invention can be prepared without mixing foreign substances, it is suitable as a carrier film for coating film production. Moreover, since it also has heat resistance, it is suitable as a release film for producing printed wiring boards.

It is a figure showing the extrusion lamination method of this invention.

Explanation of symbols

1 THV mixed resin film
2 Fluororesin film different from THV mixed resin
3 Stretched polyester film
4 Laminated film of the present invention
5 Nip roll
6 Cooling roll

Claims (14)

A THV mixed resin film containing tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymers THV1 and THV2 each having the following terpolymerization ratio is laminated on at least one surface of the stretched polyethylene terephthalate film. Film Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride 3 having a terpolymerization ratio of 40-70 wt% / 10-30 wt% / 10-30 wt% tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride 3 Terpolymer resin (THV1) and tetrafluoroethylene / tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymerization ratio of 30-50 wt% / 10-30 wt% / 30-50 wt% Hexafluoropropylene-vinylidene fluoride terpolymer resin (THV2 ). The film according to claim 1, wherein THV1 is contained in an amount of 5% by weight or more of the weight of the THV mixed resin. The film according to claim 1 or 2, wherein a film made of a fluororesin different from the THV mixed resin is further laminated on the THV mixed resin film. 4. The film according to claim 3, wherein the different kind of fluororesin is a tetrafluoroethylene-ethylene copolymer resin or a tetrafluoroethylene-hexafluoropropylene copolymer resin. 10cm length from any position on the film surface, with a terminal thickness of 5mm, and the difference (R) between the maximum and minimum measured thickness is 5μm or less. The film according to any one of claims 1 to 4. The thickness of the stretched polyethylene terephthalate film is 5 to 1000 m, the film of any one of claims 1 to 5, wherein the thickness of the THV mixed resin film is 2 to 10 [mu] m. 7. The film according to claim 3, wherein the film made of different kinds of fluororesin is a tetrafluoroethylene-hexafluoropropylene copolymer resin film having a thickness of 2 to 10 [mu] m. The film according to any one of claims 1 to 7, wherein the total film thickness is 10 to 300 µm. The film according to any one of claims 3 to 8, wherein a polyethylene film, a polypropylene film, or a polyester film is further laminated on the film made of the different kind of fluororesin. The coating film carrier film which consists of a film of any one of Claims 1-9. The film for mold release which consists of a film of any one of Claims 1-9. On at least one side of the stretched polyethylene terephthalate film,
Tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymer having a terpolymerization ratio of 40-70 wt% / 10-30 wt% / 10-30 wt% Polymer resin (THV1) and tetrafluoroethylene / hexafluorofluoroethylene / hexafluoropropylene / vinylidene fluoride terpolymerization ratio of 30-50 wt% / 10-30 wt% / 30-50 wt% Propylene-vinylidene fluoride terpolymer resin (THV2)
A method for producing a laminated film comprising laminating a THV mixed resin containing the laminate by an extrusion laminating method. 13. The method according to claim 12, wherein THV1 is contained in an amount of 5% by weight or more based on the weight of the THV mixed resin. The fluorine resin different from the THV mixed resin is laminated by extrusion lamination on at least one surface of the stretched polyethylene terephthalate film while co-extruding with the THV mixed resin. the method of.

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