JPH06136152A - Biaxially oriented polyphenylene sulfide film - Google Patents

Abstract

PURPOSE:To obtain a biaxially oriented polyphenylene sulfide film having excellent heat resistance and mechanical properties and bondability made of a composition comprising a polyphenylene sulfide and a specified amount of a polyalkylene glycol. CONSTITUTION:The film is made of a composition comprising 100 pts.wt. polyphenylene sulfide desirably one having a melt viscosity of 500-12000 P under an apparent shear rate of 200/sec at 300 deg.C more desirably one comprising at least 80mol%, based on the total repeating units, p-phenylene sulfide units and 0.01-30 pts.wt. polyalkylene glycol (e.g. polyethylene glycol).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a biaxially oriented film mainly composed of a polyphenylene sulfide film.
More specifically, the present invention relates to a biaxially oriented polyphenylene sulfide film having excellent mechanical properties and heat resistance as well as excellent adhesiveness.

[0002]

2. Description of the Related Art Polyphenylene sulfide films, especially poly-p-phenylene sulfide films, are promising and proposed for application in various fields because of their excellent mechanical properties and heat resistance. For example, JP-A-57-1210
No. 52 discloses a non-oriented sheet of polyphenylene sulfide, and JP-A No. 54-142275 discloses a biaxially oriented film. The non-oriented sheet is
Although it has a high tear strength, it has the drawbacks that when it is exposed to high temperatures, its mechanical strength rapidly decreases and its long-term heat resistance is poor. On the other hand, the biaxially oriented film has features that mechanical properties other than tear strength are significantly improved as compared with a non-oriented sheet, and chemical resistance and long-term heat resistance are extremely excellent. However, as it is expected from the structure and it is clear from the excellent chemical resistance and heat resistance, the surface is inactive, so the adhesiveness is poor, so for packaging,
In order to use it for electrical insulation, general industrial use, etc., it was necessary to impart adhesiveness.

Conventionally, a corona treatment has been disclosed as a method of imparting adhesiveness (Japanese Patent Laid-Open No. 187327/1982), but although a slight improvement over the untreated treatment is recognized, it is still insufficient. Met.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the conventional polyphenylene sulfide film, to provide a film having adhesiveness and having balanced mechanical properties and heat resistance. .

[0005]

In order to achieve the above-mentioned object, the present invention provides polyalkylene glycol in an amount of 0.01 to 3 with respect to 100 parts by weight of polyphenylene sulfide.
This is a biaxially oriented polyphenylene sulfide film containing 0 part by weight.

The polyphenylene sulfide in the present invention is intended mainly for poly-p-phenylene sulfide, and at least 80 mol% or more of all repeating units are p-.
It is composed of phenylene sulfide units. More preferably, 90 mol% or more is a p-phenylene sulfide unit. If it is less than 20 mol%, for example,

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6] Etc. may be contained as a copolymerization component, but the content of these copolymerization components is more preferably 10 mol% or less. In particular,

[Chemical 7] It is preferable that the polyfunctional copolymerization component having 3 or more functional units such as 2 mol% or less.

In the biaxially oriented polyphenylene sulfide film of the present invention, it is necessary to contain polyalkylene glycol. The polyalkylene glycol is a high polymer composed of, for example, an oxyethylene unit, an oxybutylene unit, an oxyhexylene unit, or the like, or an oxyalkylene unit formed by mixing these units. A preferred polyalkylene glycol is polyethylene glycol. The molecular weight is preferably about 400 to 1,000,000, more preferably about 400 to 20,000.

The content of polyalkylene glycol is 0.0 based on 100 parts by weight of polyphenylene sulfide.
It is 1 to 30 parts by weight, preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 3 parts by weight. If the amount is less than 0.01 part by weight, the effect of improving the adhesiveness is not seen, which is not preferable. On the other hand, if the polyalkylene glycol content exceeds 30 parts by weight, the heat resistance and mechanical properties will deteriorate, which is not preferable. The polyalkylene glycol is preferably dissolved or dispersed in the biaxially oriented film, and even when dispersed, it is particularly preferable that the major axis of the polyalkylene glycol portion is finely dispersed to 10 μm or less.

The film of the present invention is required to be biaxially oriented, and is subjected to Edg by wide-angle X-ray diffractometry.
It is preferable that the degree of orientation measured in each of the two directions e and End is 0.1 or more and 0.6 or less, and the degree of orientation measured in the Through direction is 0.7 or more.

The melt viscosity of the polyphenylene sulfide film of the present invention has a temperature of 300 ° C. and an apparent shear rate of 20.
Under the condition of 0 sec ⁻¹ , the range of 500 to 12000 poise is preferable, and the range of 700 to 7000 poise is more preferable.

The polyphenylene sulfide film of the present invention contains an antioxidant, a heat stabilizer, a lubricant, a crystal nucleating agent,
It may contain usual additives such as an ultraviolet absorber, a weather resistance agent and a coloring agent. In particular, it is preferable to add a lubricant such as inorganic or organic particles in order to form a protrusion on the film surface and impart slipperiness. These particles include silica, calcium carbonate, calcium phosphate, titanium oxide,
Inorganic particles such as kaolin, talc, alumina, zinc oxide and organic particles such as crosslinked polystyrene-based particles can be mentioned. Surface roughness of polyphenylene sulfide film (R
As a), 0.1 μm or less is preferable, and 0.01 to
0.07 μm is more preferable.

Next, the method for producing the biaxially oriented polyphenylene sulfide film of the present invention will be described.

The polyphenylene sulfide of the present invention can be synthesized by various methods. However, the method of polymerizing alkali sulfide and p-dihalobenzene in a polar solvent at high temperature and high pressure will increase the degree of polymerization of the obtained polymer. preferable.

In particular, sodium sulfide as alkali sulfide, p-dichlorobenzene as p-dihalobenzene,
Most preferably, N-methyl-2-pyrrolidone is used as the solvent.

Further, a component forming a repeating unit other than the p-phenylene sulfide unit can be added at any stage of the above-mentioned polymerization.

The polyphenylene sulfide thus obtained is supplied to a well-known melt-extruding apparatus represented by an extruder, and heated to a temperature not lower than the melting point of polyphenylene sulfide and melted. The melted polymer is a slit-shaped die (for example, T die, circular die, etc.)
It is continuously extruded from and is forcibly cooled. As the means for such forced cooling, a method of casting on a cooled metal drum, a method of immersing in a low temperature liquid, or the like can be used. In any case,
It is important to suppress crystallization (spherulite growth) of the polymer and keep it substantially in an amorphous state until just before stretching.

The polyalkylene glycol can be mixed at any stage from the synthesis of these polyphenylene sulfides to the extrusion, but the method of melt kneading with the synthesized polyphenylene sulfide to pelletize it, and then feeding it to the extruder is as follows. It is preferable because the fine dispersion of the polyalkylene glycol is enhanced.

Further, additives such as an antioxidant, a heat stabilizer, a lubricant, a crystal nucleating agent, an ultraviolet absorber, a weathering agent and a coloring agent can be mixed at any stage from synthesis to extrusion.

Next, the film thus obtained is biaxially stretched. Although the stretching method is not particularly limited, for example, a sequential biaxial stretching method using a roll group and a tenter, a simultaneous biaxial stretching method using a tenter method or a tubular method, and the like can be used. Stretching conditions vary depending on the properties of the polymer used and the stretching method, but usually the stretching temperature is in the range of 85 ° C. to 110 ° C. and the stretching ratio is 2.5 to 4.5 times in both the longitudinal and transverse directions.

The biaxially stretched film thus obtained is further heated at a temperature of 200 ° C. or higher and a melting point of the film or lower to 1 to
The film of the present invention is obtained by heat-treating for 300 seconds.

If necessary, the heat-treated film may be relaxed at a temperature equal to or lower than the melting point of the film in the range of 0 to 15% in each length and width.

[0022]

[Physical property measuring method and effect evaluating method] The characteristic value measuring method and effect evaluating method of the present invention are as follows.

(1) Melt Viscosity Using a high flow tester (manufactured by Shimadzu Corporation), 1.0
The measurement was performed at 300 ° C. using a die of mmφ × 10 mm.

(2) Strength and Elongation Tensile type tensile tester, width 10 mm, test length 50
The breaking elongation and breaking strength of the mm sample were calculated and calculated as the average value of n = 5.

(3) Melting point It was measured by the DSC method.

(4) Polyalkylene Glycol Dispersion State The film is sandwiched between two cover glasses, melted on a hot plate and then rapidly cooled to obtain a sample. The sample was observed at 200 times with a microscope and evaluated as follows from the number of polyalkylene glycol portions having a sea-island structure and having a major axis of 10 μm or more corresponding to the island portions.

◯: None at all

Δ: There are several in the visual field.

X: Many exist in the visual field.

(5) Adhesiveness A film of width W (cm) is attached to a cellotape (Nichiban Co., Ltd.).
(Made by the company) is attached, and the peeling angle is 180 degrees, and it is continuously 200 mm.
The tension when peeling at a speed of / min was measured. When the tension at this time is T (g), the peeling force = T / W (g
/ Cm).

◎: 10 g / cm or more ○: 6 g / cm to less than 10 g / cm △: 4 g / cm to less than 6 g / cm ×: less than 4 g / cm

(6) Heat resistance The film was aged in a hot air oven maintained at 260 ° C., and the strength after aging was measured by the method (2).

⊚: 80% or more of the initial value ◯: 60 to less than 80% of the initial value Δ: 40 to less than 60% of the initial value ×: less than 40% of the initial value

[0034]

EXAMPLES Next, the present invention will be described in detail with reference to examples.

Example 1 (1) Preparation of Polymer In an autoclave, 32.6 kg (25
0 mol, containing 40% by weight of water of crystallization), 100 g of sodium hydroxide, 36.1 kg (250 mol) of sodium benzoate and 79.2 kg of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were charged and stirred. Gradually 2
The temperature was raised to 05 ° C., and the distillate containing 6.9 kg of water was 7.0 liters.
Was removed. To the remaining mixture, 37.5 kg (255 mol) of 1,4-dichlorobenzene (hereinafter referred to as DCB) and 20.0 kg of NMP were added and heated at 265 ° C for 4 hours. The reaction product was heated and washed 3 times with NMP, further washed 3 times with hot water, and dried at 80 ° C. for 24 hours using a vacuum dryer to obtain 21.1 kg of polyphenylene sulfide powder.
(Yield 78%) was obtained. The melt viscosity of the polymer is 3800 poise at 300 ° C. and a shear rate of 200 sec ⁻¹ , Tm 285.
It was ℃.

Then, to 10 kg of the obtained powder, 150 g of ethylene glycol slurry of spherical silica having an average diameter of 0.5 μm (solid content concentration 20%) and 50 g of polyethylene glycol (molecular weight 4000) were added, and the mixture was heated at 50 ° C. using a Henschel mixer. And stirred at high speed.

This mixture was fed to a counter-rotating twin-screw extruder having a single-stage vent hole and melted at 310 ° C., and ethylene glycol was removed from the molten resin at the vent section. Then, the molten polymer was extruded from a 3 mmφ die to obtain pellets.

(2) Preparation of film The pellets obtained in (1) are put into a hopper of an extruder having a diameter of 40 mm and the air in the hopper is replaced with nitrogen gas. It was melted at 310 ° C., extruded from a T-die having a straight lip, cast on a metal drum whose surface temperature was kept at 30 ° C., and cooled and solidified. At this time, wire is stretched on the drum and cast while applying a DC voltage of about 5 kV between the wire and the drum (electrostatic cast)
did. The obtained unstretched sheet had a thickness of 260 μm.

Next, the unstretched sheet was stretched by a simultaneous biaxial stretching device at 95 ° C. for 3.5 × 3.5 times to obtain a biaxially stretched film.

Finally, the above biaxially stretched film was heat-treated at 250 ° C. for 60 seconds under a constant length to obtain a biaxially oriented polyphenylene sulfide film having a thickness of 21 μm. The characteristics of the obtained film are shown in Table 1.

Example 2, Example 3, Comparative Example 1, Comparative Example 2 A biaxially oriented film was prepared in the same manner as in Example 1 except that polyethylene glycol was not added or the compounding amount was changed as shown in Table 1. Obtained. The characteristics of the obtained film are shown in Table 1.

Examples 4 and 5 Polyethylene glycol having a molecular weight of 600 and 20
A biaxially oriented film was obtained in the same manner as in Example 1 except that the film of 000 was used. The characteristics of the obtained film are shown in Table 1.

Example 6 A biaxially oriented film was obtained in the same manner as in Example 1 except that polytetramethylene glycol (molecular weight 1000) was used instead of polyethylene glycol. The characteristics of the obtained film are shown in Table 1.

[0044]

[Table 1]

[0045]

INDUSTRIAL APPLICABILITY The biaxially oriented polyphenylene sulfide film of the present invention has a heat resistance inherent to the polyphenylene sulfide film due to the addition of polyalkylene glycol.
The film has mechanical properties and the like, and the adhesiveness, which has been a drawback of the conventional polyphenylene sulfide film, is remarkably improved.

Therefore, it can be widely used as a dielectric of a capacitor, a tape, an electric insulating material, a flexible printed circuit board, a base of a magnetic recording medium and the like. In particular,
It is most suitable for places where it is used by adhering to other materials such as variable capacitors and adhesive tape.

Claims (1)

[Claims] 1. A polyalkylene glycol is added in an amount of 0.01 to 30 with respect to 100 parts by weight of polyphenylene sulfide.
A biaxially oriented polyphenylene sulfide film containing 1 part by weight.