JPS6137419A - Biaxially oriented thermoplastic polyetherether ketone film - Google Patents

Abstract

PURPOSE:To make it possible to obtain a film excellent in heat resistance and stable in mechanical properties and dimensional accuracy within a wide temperature range, by selecting a film wherein the melt viscosity at a 350 deg.C under a shearing rate of 200(sec)<-1> is 200 to 300,000 poises and the density at 25 deg.C is 1.260-1.310. CONSTITUTION:The melt viscosity of the thermoplastic polyetherether ketone resin used in the present thermoplastic polyetherether ketone film should be, at a 350 deg.C under a shearing rate of 200(sec)<-1>, 200 to 300,000 poises. If the melt viscosity is less than 200 poises, the film is too brittle to give a practical film, and if the melt viscosity is over 300,000 poises, filming by melt extrusion becomes difficult. The film obtained after biaxial orientation should also has almost the same melt viscosity under the same conditions. The density of the thermoplastic polyetherether ketone film after biaxially oriented and thermosetting should be 1.260-1.310. If the density is less than 1.260, the mechanical properties are low, and the film is apt to become brittle, and if the density exceeds 1.310, the flexibility and the tear resistance decrease significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a biaxially oriented thermoplastic polyether ether ketone film that has excellent heat resistance and stable mechanical properties and dimensional accuracy over a wide temperature range.

[Prior art]

Heat-resistant resins such as polyamide, polyimide, polyester, and polysulfone are being considered in order to obtain materials with heat resistance, mechanical properties, and dimensional accuracy that far exceed those of conventional polyethylene terephthalate film, but there are no materials that satisfy these requirements and can be melt-formed into films. It hasn't been discovered yet.

On the other hand, thermoplastic polyether ether resin has extremely high heat resistance and is being used in many fields as a resin with unique properties such as mechanical strength, flame retardance, and chemical resistance. - In order to obtain a high-performance film that far exceeds that of polyethylene terephthalate film, we investigated various polymers, and as a result of our research, we focused on this thermoplastic polyetheretherketone, which can be melt-formed, and obtained a practical film from it. The present invention was achieved by developing a method.

[M1 composition of the invention] That is, the present invention is a biaxially oriented film consisting essentially of thermoplastic polyetheretherketone, which has a melt viscosity at 350° C. at a shear rate of 200 (sec.)”-
The present invention relates to a biaxially oriented thermoplastic polyether ether ketone film, characterized in that it has 200 or more and 30,000 or less voids and a density of 1.260 to 1.310 at 25° C.

The thermoplastic polyetheretherketone in the present invention is a polymer in which 90 moles or more of the constituent units are composed of constitutional units, but it may contain other copolymerized units as long as it is less than 10 moles. Examples of the relevant copolymerized units include the following: Examples include structural units.

A is a direct bond, -0-1-S-1-SO2-1-CO-
It is a mono- or divalent hydrocarbon group. ) A simple method for synthesizing thermoplastic polyetheretherketone comprising such a structural unit is to react 4,4'-difluorobenzophenone, hydroquinone, and anhydrous potassium carbonate in a polar solvent at high temperature. The polymerization temperature is preferably 170 DEG C. to 330 DEG C., and other parameters such as pressure and polymerization time are varied depending on the desired degree of polymerization and molecular weight.

On the other hand, the film forming method is a melt film forming method in which a polymer is placed into a film shape by extrusion through a die, etc., and then rapidly cooled to produce a non-quality film. At this time, the cooling rate was set to 5'C/3C (,
Maintain the temperature above to reduce the crystallinity and form a transparent film. If the cooling rate is less than 5° C./sec0, it becomes monocrystalline and becomes opaque.

This non-quality film is heated to around the glass transition temperature of the polymer.
At 50° C. to 210° C., it is stretched simultaneously or sequentially biaxially with a roll or tenter to an area magnification of 3 times or more, preferably 5 times or more, and further under tension at 200° C. to 330° C. (melting point of the polymer). Preferably, it is heat-set by heating at 250° C. to 310° C. for 1 second to 5 minutes.

The heat setting time is determined by the target high summer temperature and is 1.260 to 1.310 for 1 second to 5 minutes, and if heat setting is not performed, the film will be heated above the stretching temperature. , it causes significant shrinkage and opacity, making it impractical.

The film obtained in this way has excellent heat resistance, mechanical properties, and stable dimensional accuracy, and does not become opaque or brittle even when heated close to the melting point of this polymer, making it a practical heat-resistant film. It turned out to be a performance film.

The melt viscosity at 350°C of the thermoplastic polyetheretherketone resin used in the biaxially oriented thermoplastic polyetheretherketone film of the present invention is at a shear rate of 200°C.
(sec.) -1, the poise is 200 to 300,000 poise, and if the poise is less than 200, the film will be brittle and not practical, and if it exceeds 300,000 poise, it will be difficult to form a film by melt extrusion. Note that the melt viscosity of the film after biaxial orientation also remains almost unchanged under the same conditions, ranging from 200 to 300,000 poise.

Further, the density of the thermoplastic polyetheretherketone film after biaxially oriented heat setting at 25°C is 1.260 to 1.
If it is less than 1.260, the mechanical properties will be low and it will be easily brittle, and if it exceeds 1.310, the flexibility and tear strength will be significantly reduced.

〔Effect of the invention〕

The biaxially oriented thermoplastic polyether ether ketone film of the present invention is suitable for the fields of electrical and electronic parts such as capacitors, electrical coatings, and flexible printed circuit boards, and precision parts such as recording medium bases.

〔Example〕

Example 1 Thermoplastic polyetheretherketone (Polyetheretherketone 451GV manufactured by ICI) had a melt viscosity of 900 at 350°C and a shear rate of 200 (sec, )-'.
It is 0 poise. This was pressed at 350℃.

Shape and quench in 10℃ water within 10 seconds to a density of 1.250.
A transparent, almost amorphous film was obtained. 3. Stretch this film on a film stretcher at 5165°C. OX
3. Biaxial stretching was performed at O times the amount. The density of the film after stretching is 1.250, which is the same as before stretching.Furthermore, the film after stretching is fixed at full bending angle and heat set at -300°C for 30 seconds to give a haze of 4. -01, a 10μ film with a density of 1.300 was obtained.

Melt viscosity was measured using a Koka type flow tester made by Shimayo Seisakusho.
The haze was measured using a die of 1.0 mm x 10 mm, and the haze was measured using a haze meter manufactured by Nippon Denshoku Kona.

Comparative Example 1 The transparent film obtained in Example 1 after press molding was heated to 180°C.
If heated above this temperature, it becomes cloudy and a practical film cannot be obtained.
In addition, when the film immediately after stretching is heated to 150°C or higher, the
% or more, and when further heated to about 200° C., the film turned white and became brittle, making it impossible to obtain a practical film.

Comparative Example 2 In a three-way glass flask equipped with a stirrer, a nitrogen inlet tube, and a near condenser, 0.10 mol of 4,4'-difluorobenzophenone, 0.10 mol of hydroquinone, and 60 r of diphenyl sulfone were placed while stirring. It was heated to 180° C. to give an almost colorless solution and 0.101 mole of anhydrous potassium carbonate less than 300 μm was added while maintaining a nitrogen bracket. Heat this to 200℃~320℃
Polymerization was carried out by stirring while gradually raising the temperature to 'C. The polymerization time was carried out at two levels, 1 hour and 10 hours, and after the polymerization was completed, they were cooled, pulverized, and precleaned to remove diphenylsulfone and inorganic salts. The obtained solid polymer was vacuum dried at 140°C.

The melt viscosity of these polymers at 350°C is 150 poise/20.0° (sec) when polymerization time is 1 hour.
, )-', 10 hours is 350,000 voices/200
(sec,)-1.I attempted to prepare a film using the same method as in Example 1, but the film with a polymerization time of 1 hour was brittle and simultaneous biaxial stretching was not possible. Both had poor stretchability and could not be made into practical films.

Claims (1)

[Claims] A biaxially oriented film consisting essentially of thermoplastic polyetheretherketone, the melt viscosity at 350° C. being 20 at a shear rate of 200 (sec.)^-^1.
0 or more and 300,000 poise or less, and the density at 25°C is 1
．． 260 to 1.310.