JPS6312772B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a poly p-phenylene sulfide film having excellent thermal, mechanical and dimensional stability properties. Over the past few years, there has been a great deal of interest in manufacturing research and commercialization of heat-resistant films. In particular, there has been a growing need for films that are melt moldable and have excellent thermal, mechanical, dimensional stability, and electrochemical properties. Polyethylene terephthalate film has traditionally been a film with extremely well-balanced properties, but this film does not reach the so-called F grade for electrical insulation thermally, and there is a need for a film that is even better. There is. In addition, polyimide film has a heat resistance that far exceeds that of Type F, but the film forming method is a solution method, resulting in poor productivity and very high costs.
F, which is currently ranked one step higher in heat resistance than well-balanced polyester films.
A film that has seed insulation and can be melt-formed has not been found, so we paid attention to this point, made efforts to develop a new film, and arrived at the present invention. An object of the present invention is to provide a film with excellent heat resistance, mechanical properties, dimensional stability, transparency, and electrochemical properties. In order to achieve the above object, the present invention has the following configuration, that is, the present invention has the general formula

Relative crystal containing 90 mol% or more of the structural unit represented by the formula, with a melt viscosity of 100 to 600,000 poise at 300°C and a shear rate of 200 (seconds) ^-1 , and measured by wide-angle X-rays. degree of crystallization 5-35, microcrystal size 40-130
It is characterized by a poly p-phenylene sulfide film whose degree of orientation measured from the Å, Edge and Endo directions are all 0.1 to 0.6. The polymer used in the present invention has the general formula

It is necessary to contain 90 mol% or more of the structural unit represented by the formula; if it is less than this, it is difficult to obtain a film with excellent properties. There are various methods for polymerizing this polymer, and there are no particular limitations. However, a method in which alkali sulfide and p-dihalobenzene are used in a polar solvent using a polymerization aid is preferred because the degree of polymerization of the resulting polymer is easily increased. Especially sodium sulfide and p
An excellent method is to polymerize dichlorobenzene under pressure in a high-boiling polar solvent such as N-methylpyrrolidone using a metal salt of a carboxylic acid. If it is less than 10 mol% as a copolymer component, it is a meta bond.

[Formula] Ether bond

[Formula] Sulfone bond

[Formula] biphenyl join

[Formula] Naphthyl bond

[Formula] Substituted phenyl sulfur id join

[Formula] where R represents an alkyl, nitro, phenyl, or alkoxy group), trifunctional phenyl sulfide bond

[Formula] and the like may be contained as long as they do not significantly affect the crystallinity, stretchability, and orientation of the polymer, but preferably the copolymerization component is 5 mol % or less. In particular, the content of the trifunctional or higher functional copolymerization component is preferably 1 mol % or less. The viscosity of the polymer used in the present invention is 300℃,
100 to 600,000 poise, preferably 300 to 100,000 poise at a shear rate of 200 (seconds) ^-1 ,
Further, it is preferable that the non-Newtonian coefficient (n) (obtained from the slope of shear rate and shear stress) is 0.8 to 2.0. Polymers with extremely low or high viscosity or n>3.0 outside of these melting property ranges may not be stable in melting and discharging, or the surface shape of the discharged film may be unfavorable, resulting in uneven thickness, uneven stretching, etc.
This is undesirable as the surface becomes uneven. Here, the non-Newtonian coefficient is defined by the following formula. γ=1/ ^μτ nwhere γ=shear rate, μ=viscosity constant, τ=
Shear stress, n = non-Newtonian coefficient. The following three structural parameters of the film in the present invention must be satisfied. First of all, the relative crystallinity is determined by the maximum intensity of the (200) peak (I ₂₀₀ ) from the diffraction profile of the film using wide-angle X-rays.
The intensity (I ₂₅ ) at 2θ=25° is measured and the ratio of the two is I ₂₀₀ /
Relative crystallinity is defined as _I25 , and this value must be in the range of 5 to 35. In other words, if it is less than 5, the crystallinity will be insufficient, and the film will have poor dimensional stability when heated to high temperatures and will not have sufficient heat resistance. On the other hand, it is actually difficult to obtain a film that exceeds 35, and even if it were obtained, it would be quite brittle. Second, the size of the microcrystals must be within a certain range, which is smaller than the half-width of the (200) diffraction peak.
It refers to the apparent crystal grain size (ACS) obtained using Scheller's formula, and it needs to be between 40 and 130 Å. As a result of various studies, this
The correlation between ACS and film physical properties is the film's heat resistance,
There is a close relationship with mechanical properties, particularly Young's modulus and thermal distortion properties, and if the ACS is less than 40 Å, these properties deteriorate. Furthermore, when the film is grown to a thickness of 130 Å or more, the embrittlement of the film becomes noticeable. The third necessary parameter is the degree of orientation, and this parameter is related to the edge and
Take an X-ray plate photograph from the Endo direction,
The ratio of the degree of blackening (I〓 ₌₀゜) when the intensity of the (200) surface is scanned in the radial direction with a densitometer on the equator line and the degree of blackness in the 30゜ direction (I〓 ₌₃₀゜), that is, I〓 ₌₃₀゜/I〓 _{If =0}゜ is defined as the degree of orientation (OF), the preferable range is
It is 0.1-0.6. Here, Edge is an X-ray incident from a direction parallel to the long axis, and Endo is an X-ray incident perpendicular to this and also perpendicular to the thickness direction. this
OF is related to film transparency, thermal dimensional change, mechanical properties, etc., and films with values exceeding 0.6 are inferior in these properties. For example, in the case of fibers or uniaxially oriented films, the Endo direction value exceeds 0.6, making it impossible for the film to be a useful film that has properties above a certain level in any direction within the film plane. Also
Films with a molecular weight of less than 0.1 are difficult to obtain using normal methods, and even if they are obtained, tearability and other properties will deteriorate. Next, a specific film manufacturing method for satisfying each numerical value of the present invention will be described below. The simplest method for crystallizing a film and keeping its properties within a certain range is a combination of orientation by stretching or drafting and crystallization by heating using a polymer with a low degree of crosslinking. For example, density 1.310 cooled at a rate of at least 10°C/sec after melting and dispensing.
~1.330g/cc mostly amorphous film 85~110
A method of simultaneously or sequentially stretching at an areal magnification of 8.5 to 21 times at a temperature range of 8.5 to 21 times to achieve biaxial orientation, followed by heat setting under tension at 150 to 275 °C, preferably 200 to 275 °C, for 1 to 300 seconds. The so-called tubular method involves blowing gas into the film after melting and discharging it from a circular die to achieve orientation at the same time as the film expands, followed by heat setting under tension at 150 to 275°C, preferably 200 to 275°C, or orientation by rolling. An example of this method is to combine orientation by stretching and then heat setting at the above temperature. Of course, changes in the relative crystallinity, OF, and ACS of the film during film formation can be considered, but it is not possible to obtain an excellent final film unless these three parameters are within a certain range. The most preferred method that can be employed industrially is a method of sequential biaxial stretching and subsequent heat setting. Note that the film of the present invention may be mixed with other polymers and fillers, and may also contain antioxidants,
Additives such as ultraviolet absorbers may also be contained. Furthermore, the film of the present invention may be composited with other films or coated with other materials. In the film of the present invention, the three crystal-related structural parameters each independently or jointly have a close correlation with the film properties. In other words, only when these parameters are satisfied can a film with excellent heat resistance, mechanical properties, dimensional stability, transparency, and electrochemical properties be obtained. The film obtained according to the present invention takes advantage of these properties and can be used for packaging, photography, etc.
It can be used as a material for magnetic recording, electrical insulation, adhesive tape bases, building materials, decorations, etc. Here, the measurement method of the present invention will be explained. Melt viscosity was measured at 1mm using a Koka type flow tester.
Measurements were made using a cap with a diameter and length of 10 mm at 300°C and a shear rate of 200 (sec) ^-1 . Next, a method for measuring the three parameters using X-rays will be described. CF: The thickness of each sample is 1 mm, with the stretching direction aligned.
Formed into a strip with a width of 1 mm and a length of 10 mm (each film was fixed using a 5% aluminum acetate solution of collodion during forming), and X-rays were incident along the film surface of the film (Edge and Endo directions). I then took a photo of the plate. The X-ray generator was a Rigaku D-3F type device, and the X-ray source was Cu-Kα rays passed through a Ni filter at 40 KV and 20 mA. The distance between the sample and the film was 41 mm, and a multiple exposure (15 and 30 minutes) method was used using Kodatsu non-screen type film. Next, measure the intensity of the (200) peak on the plate photograph by scanning the densitometer in the radial direction from the center of the photograph at φ = 0° (on the equator line), 10°, 20°, and 30°, and read the degree of blackening for each. The degree of orientation (OF) of the sample was defined as OF=I〓 ₌₃₀゜/I〓 ₌₀゜. Here, I〓 ₌₃₀゜ is the maximum intensity of the 30゜ scan, and I〓 ₌₀゜ is the maximum intensity of the equatorial line scan. In addition
I〓 ₌₀゜ is φ＝0゜ and φ＝180゜, I〓 ₌₃₀゜ is φ＝30゜ and φ＝
The average value of the intensity at 150° was used. Here, the measurement conditions of the densitometer are as follows. The device used was Sakura Microdensitometer Model PDM-5 Type A manufactured by Roku Konishi Photo Industry, and the measurement concentration range was 0.0 to 4.0D (minimum measurement area 4μ ² conversion).
The optical system has a magnification of 100 times, a slit width of 1 μ and a height of 10 μ, a film movement speed of 50 μ/sec, and a chart speed of 1 mm/sec. ACS and relative crystallinity: The sample was rotated in the plane to eliminate the sample orientation effect, and the diffraction pattern was measured using the reflection method. The X-ray generator is a Rigaku D-8C type device, 35KV.
The X-ray source was Cu-Kα passed through a Ni filter at 15 mA. The goniometer was a Rigaku Denki model PMG-A2, and the sample was mounted on a rotating sample stage that rotated at a rotation speed of 80 rpm.
Receiving slit 0.15mm and scattering slit 1° were adopted. 2θ scan speed is 1/min, chart speed is 1
cm/min. Each sample was cut into a square with a side of 20 mm and stacked to a thickness of 0.5 mm to serve as a measurement sample. The apparent crystal size (ACS) was calculated from the half-width of the (200) diffraction peak using Scheller's equation. ACS (Å) = Kλ/βcosθ, β = [B ² − (B′) ² ] ^1/2 where K: Scheller constant (K = 1) λ: X-ray wavelength (λ = 1.5418 Å) 2θ: Bragg angle (°) β: Half-width after correction (radian) B: Actual half-width B′: Half-width of standard sample for correction (Si single crystal) The relative crystallinity is determined from the diffraction profile of each sample (200 ) The maximum intensity of the peak (I ₂₀₀ ) and the intensity at 2θ=25 (I ₂₅ ) were measured as internal standard values, and the ratio of the two was defined as the relative crystallinity (I ₂₀₀ /I ₂₅ ). The present invention will be explained below with reference to Examples. Examples 1 to 3, Comparative Examples 1 to 5 1 mol of sodium sulfide nonahydrate, 0.15 mol of sodium hydroxide, 0.8 mol of sodium benzoate, and 400 ml of N-methylpyrrolidone were placed in an autoclave and gradually heated to 200°C in a nitrogen stream. Dehydration was performed by heating. The system was then cooled to 170°C, 1.01 mol of p-dichlorobenzene was added together with 200 ml of dehydrated N-methylpyrrolidone, and the system was pressurized to 4.0 Kg/cm ² with nitrogen. The system was heated to 270°C with stirring. Polymerization was carried out for 5 hours. After the polymerization was completed, the contents were poured into a large amount of water to isolate the polymer, followed by repeated washing with hot water and acetone to obtain a white bead-like polymer.
This polymer had μ=2200 poise and n=1.12. After melt pressing the dried polymer at 300℃,
Quenched into cold water at ℃ to form a mostly amorphous material with a density of 1.325.
A 200μ film was obtained. TMLong this film
The film was simultaneously biaxially stretched under various conditions using a film stretcher manufactured by the company, and heat-set. The structural parameters and physical properties of the film were measured using X-rays, and the results shown in Table 1 were obtained. It can be seen that Examples 1 to 3 of the present invention are superior in thermal and mechanical properties as compared to comparative examples other than the present invention.

【table】

[Table] Example 4, Comparative Example 6 Examples 1 to 3 except that a mixture of 1.00 mol of p-dichlorobenzene and 0.002 mol of 1,2,4-trichlorobenzene was used instead of 1.01 mol of p-dichlorobenzene. Polymerization was repeated to obtain a flaky polymer with μ=5600 poise and n=1.44. This polymer
After melt pressing at 310℃, quenching in ice water to reduce density.
An almost amorphous 250μ thick film of 1.326 was obtained. This film was sequentially stretched biaxially using a TMLong film stretcher and heat-set at 270° C. for 60 seconds to obtain a film. The film forming conditions, structural parameters, and physical properties of the film are shown in Table 2, and it has been found that a good film cannot be obtained unless the three structural parameters of the present invention are simultaneously satisfied.

【table】

[Table] Comparative Example 7 In Example 1, when 1.2 mol of p-dichlorobenzene was used instead of 1.0 mol of p-dichlorobenzene, a powdered polymer with μ=150 poise and n=1.02 was obtained. Obtained. This polymer was melt-pressed at 300°C and then rapidly cooled in ice water to obtain an amorphous film, but it was quite brittle and could be stretched to a maximum of 1.2 times at 90°C, so the viscosity was too low to obtain a useful film. Furthermore, when the structural parameters of the amorphous film were measured, it was found that OF = 1.00, ACS = 20 Å, and the relative crystallinity was 1.5 or less.

Claims (1)

[Claims] 1 Contains 90 mol% or more of the structural unit represented by the general formula [Formula], and has a melt viscosity at 300°C of 100 to 600,000 poise at a shear rate of 200 (sec) ^-1 , And the relative crystallinity measured by wide-angle X-rays is 5-35, the size of microcrystals is 40-130 Å, and the degree of orientation measured from the Edge and Endo directions is both 0.1-35.
0.6 poly p-phenylene sulfide film.