JPS58201617A - Polyp-phenylenesulfide film - Google Patents

Abstract

PURPOSE:To provide a polyP-phenylenesulfide film composed of a polymer of specific fused viscosity which has a high maintenance rate of tensile strength and stress when elongated after heat treatment comparing with its values before heat treatment and is excellent in heat resistive durability, mechanical properties and heat resistive dimensional stability and useful for the manufacture of electronic parts. CONSTITUTION:The film is composed of polyP-phenylenesulfide having a repetition unit represented by the formula, and a polymer of which fused viscosity is more than 12dl/g is press formed into a film at a temperature of 310 deg.C and it is quickly cooled in water to produce a transparent sheet not elongated yet, and after that, the sheet is biaxially elongated simultaneously at a temperature of 94 deg.C and a film thus obtained containing repetition unit represented by the formula by more than 90mol% is cut into pieces of film measuring 10mm. in width and 100-150mm. in length, and they are heat treated in loose condition at 270 deg.C for 10min, and the intended film having such maintenance rates of tensile strength when it is elongated at the rate of 200%/min at 23 deg.C, stress and elongation degree at the time of elongation rate of 5% which are higher than those values before heat treatment by more than 60%, 80% and 80-120% respectively can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a poly p-phenylene sulfide film having excellent heat aging resistance, mechanical properties, and heat resistant dimensional stability.

2. Description of the Related Art In recent years, technological progress and expansion of applications of electronic and electrical devices have been remarkable, and electronic devices are rapidly becoming more sophisticated, more reliable, smaller, lighter, and less expensive. For this reason, the requirements for mechanical, electrical properties, high dimensional stability, etc. for the film materials used are becoming increasingly strict. Currently, polyimide is used as a heat-resistant film, but it has many disadvantages such as high price and poor chemical resistance. Polyethylene terephthalate films have also been used.

This film is inexpensive and has excellent mechanical and electrical properties as well as chemical resistance, but its melting point is low at around 260°C, making it difficult to mount electronic components by soldering at around 260°C. I can't do it @There is a problem with heat.

The present invention aims to compensate for the shortcomings of these existing films and provide a film with well-balanced mechanical properties, electrical properties, and heat resistance, and in particular, a film with extremely excellent dimensional stability under heat. The present invention provides a film having the following characteristics.

That is, the present invention is a poly p-phenylene sulfide film containing 90 mol% or more of repeating units +S+,
The solution viscosity of the polymer was 0.12 dl/g or more, and the film was cut out into 10-100 mm lengths in the vertical and horizontal directions, and heat treated at 270°C for 10 minutes in a relaxed state. °C, tensile strength when elongated at a rate of 200%/min, stress at 5% elongation (hereinafter referred to as
F-5 value), each value of elongation is 60% or more compared to each value of tensile @ charcoal, F-5 value, and elongation when the film before heat treatment is subjected to a tensile test under the same conditions. , more than 80%,
A biaxially oriented poly p-phenylene sulfide film having a retention rate of 80 to 120% is provided.

There are methods for synthesizing aromatic dihalides by sulfurization, and methods for desalting thiophenol salts. Industrially p
The most preferred method is to carry out a hinoki polymerization reaction in a p-dihalobenzene such as -dichlorobenzene and an amide polar solvent such as sulfurized sortara N-methylpyrrolidone. Further, the polymer component of the film of the present invention is prepared using α-chlornaphthalene as a solvent at a temperature of 206°C and a concentration of 0.4 g.
/100m7! When the value is 0.12 dJ/g or less, preferably 0.12 to 1. Odl/g. For example, the following three methods can be used to obtain a polyphenylene sulfide polybute having such a solution viscosity.

First, during polymerization, a carboxylic acid alkali metal salt or alkaline earth metal salt such as lithium acetate, sodium acetate, calcium acetate, sodium benzoate, or lithium benzoate is added in an amount of about 10 to 150 mol% of the monomer. Therefore, there is a method to increase the molecular weight of the produced polymer. Secondly, 2 such as p-dichlorobenzene is used as a monomer during polymerization.
In addition to the blinding compound, there is a method of increasing the solution viscosity by introducing some crosslinking structure into the polymer using, for example, 1,2,4-)dichlorobenzene, which is mainly used in combination with the first method. In this case, the mixing ratio of the trifunctional monomer to the main monomer is at most 10 mol% or less, preferably 1 mol% or less. A third method is to expose the polymerized low viscosity polymer to air at a temperature ranging from 200° C. to below the melting point to promote oxidative crosslinking and increase the solution viscosity of the polymer. However, although this method may be preferable when used in combination with the first method, it is not preferable for the present invention to use a polymer whose solution viscosity in Polymerization 11m is too low after being oxidized and crosslinked using a fist method. For example, even if a polymer having a solution viscosity of 0.10 is used as a polymer having a solution viscosity of 0.30 dl/g or more by oxidative crosslinking, the polymer becomes almost impossible to stretch. The second and third methods are preferable when a moderate amount of crosslinked structure is introduced into the polymer as a raw material of the present invention, but if the crosslinked structure is introduced too drastically, the polymer exhibits rubber elasticity when melted and stretched. This often results in a film with poor flatness or poor stretchability, making it impossible to obtain a film with the characteristics of the present invention.

In order to satisfy the present invention, it is necessary that phenylene sulfite units exist in the polymer in an amount of 90 mol% or more (eg, phenyl, alkoxy, sulfone, halogen, carboxylic acid, metal salt of carboxylic acid, etc.), and The above-mentioned trifunctional compounds may also be used.

The above polymers are used as raw materials for the present invention, and include lubricants, antioxidants, ultraviolet absorbers, plasticizers,
There is no problem in mixing additives such as colorants, or blending and using polymers and inorganic fillers within a range that does not impede the purpose of the present invention.

To make one film of the present invention, the above raw materials are first formed into a sheet or film using an extruder, press, etc., and then rapidly cooled using liquid nitrogen, water, a roll, etc. to a density of 1.330 g/ A nearly amorphous unstretched film having the following properties is obtained. If the crystallization of the unstretched film progresses, the stretchability will decrease and the film will be more likely to break during stretching.

Next, stretching is performed. Although the stretching temperature varies somewhat depending on the molecular weight and components of the polymer, it is usually desirable to be near the glass transition temperature of the polymer, specifically 80 to 120°C, preferably 90 to 110°C. As a stretching method, a commonly used stretching method such as a roll method, a tenter method, or a Chevler method is convenient. The stretching ratio should be 2.5 to 7 times, preferably 2.5 to 6 times, in view of the physical properties and productivity of the resulting film (regardless of whether simultaneous biaxial stretching or sequential stretching is used). good.

In order to increase the density of the biaxially stretched film and improve its dimensional stability, heat resistance, mechanical strength, etc., heat treatment is particularly necessary to satisfy the mechanical properties that the film of the present invention must have. and crystallize it. Heat treatment conditions include melting point (↑-350℃ or lower,
Preferably, it is necessary to carry out the process at a temperature of 111 to 340°C [1F+, under tension, for a time of 120 seconds or less. This heat treatment yields a poly p-phenylene sulfide film with excellent heat resistance and dimensional stability. Here, the melting point (Ts+) is 2
This is the melting point obtained by DSC (differential scanning calorimetry) of the film immediately after axial stretching. At this time, if the heat treatment temperature exceeds 6-350 DEG C., the film becomes molten and cannot maintain its shape even if the heat treatment time is shortened. 1 if the temperature range is T-~350℃
By appropriately adjusting the heat treatment time to within 20 seconds, the film can be heat-set without becoming molten.

In order to obtain the film of the present invention, if necessary, before and after the above-mentioned heat treatment process, within a temperature range of 150 to 3'JO °C, preferably 200 to 340 °C, within 25% in one direction or two directions, Heat shrinkage can be reduced and dimensional stability under heating can be improved by appropriately treating the film under limited shrinkage or elongation or constant length, preferably within 15%, within 10 minutes. .

The above heat treatment is performed by bringing a heated gas, liquid, or solid into contact with the film before heat treatment.

It is also possible to use radiation such as an infrared heater, ultrasonic waves, or high frequency irradiation. In the present invention, the "ra degree" and "time" of heat treatment refer to the temperature of the heating medium and the contact time to the heating medium in the case of using a medium, and in the case of using an infrared heater, ultrasonic wave, or high frequency, film temperature and processing time.

Heat resistance in a practical sense has various meanings, but one of the most important is dimensional stability during solder immersion. 11 electronic or electrical parts! Soldering is the most common method for mounting l'm. Materials whose dimensions change during the soldering process cannot be used in electronic or electrical equipment that requires precise dimensional control.

In order to improve the dimensional stability during solder immersion, the present inventors conducted detailed studies on the relationship between polymers of various compositions, film manufacturing conditions, and the dimensional stability of the final film.

As a result, the film of the present invention, in which the strength and elongation retention of the film heat-treated at 270°C for 10 minutes in a relaxed state, is a certain value or more, exhibits uniquely excellent dimensional stability when immersed in solder. That is, the film of the present invention has a width of 10tI and a length of 100"15 in the longitudinal and transverse directions.
The tensile strength, F-5 value, and elongation values when the film was cut out to 0 m, heat-treated at 270°C for 10 minutes in a relaxed state, and then stretched at 23°C at a rate of 200%/min were as follows: 60% or more, 80% or more, and 80% of each value of tensile strength, F-5 value, and elongation when stretched under the above conditions, respectively.
~120%, preferably 60-110%, 80% respectively
By having retention rates of ~110% and 90-120%, it shows excellent dimensional stability during solder immersion.

The method for producing a poly p-phenylene sulfide film having such mechanical properties is as described above, but stretching conditions such as stretching temperature and stretching ratio as well as heat treatment conditions for crystallization are particularly important. The optimal processing conditions vary slightly depending on the composition of the polymer, but it is possible to use a polymer containing 90 mol% or more of +S- repeating units, or a polymer composition containing this as the main component and a small amount of additives or a blend polymer as a raw material. A film having the mechanical properties shown in the present invention obtained under the above manufacturing conditions exhibits excellent soldering heat resistance.

The film of the present invention has excellent 1-da heat resistance, and also has excellent long-term heat resistance, passing F-4 (IEcIl rating P).
It can be used as a heat-resistant film for ub86).

The film of the present invention is most suitable as an electrically insulating film. For example, a base film for flexible printed wiring; as an insulating material for 11-rotation machines such as vehicle motors, refrigerator motors, and generators, or various vinegar machines, and as insulation for covering general cables, high voltage, and ultra-high voltage cables. Material: Base film for magnetic tape: Useful as a Condensation film. It is also suitable as an insulating material for dry type and oil-immersed transformers. Furthermore, in addition to electrical insulating materials, it is also used in copying films, tracing films, and food packaging materials used in high-temperature cooking, which are exposed to high temperatures during processing and require dimensional stability. It is also useful for decorative purposes, building materials, photographic films, acoustic uses such as bases for magnetic disks and diaphragms for 9-cars, diaphragms for batteries, and base materials for hot stamping. It is also possible to use it as a composite material by laminating it with other films or combining it with metals, paper, etc.

The present invention will be explained below with reference to Examples.

In addition, the tensile test in Examples was conducted under the following conditions.

Medium 10mm in vertical and horizontal directions, length 100-150
The sample was cut out to a length of 1.5 m, and elongated at a measurement temperature of 23° C. at a rate of 200%/min.

Example 1 1.8 k of N-methylpyrrolidone in a 51 autoclave
g and sodium sulfide 2.7 hydrate 0.5 kg and sodium benzoate 0.6 b, sodium hydroxide 1.6
After cooling the reaction system to 170°C, the temperature was gradually raised to 200°C under nitrogen atmosphere with stirring for about 2 hours, and 5.105ml of water was distilled out. 0.6 kg of benzene and 0.4 kg of N-methylpyrrolidone
kg was added and reacted at 220°C for 2 hours and then at 250°C for 3 hours. Internal pressure at the end of polymerization is 6.7kr/cia
Met.

After cooling the reaction system, the contents were separated by filtration, and the solid content was evaporated with hot water.
1! After washing twice with acetone and drying at 120° C. for 3 hours, a gray, granular polymer was obtained. The solution viscosity of this polymer was determined using α-chlornaphthalene.
When measured at a temperature of 206℃ and a 10-concentration of 0.4g/100ml, it was 0.29d.
It was l/g.

This polymer was pressed at 310°C and quenched in water to obtain a transparent unstretched sheet with a thickness of 400 microns.

The density of this sheet was 1.321 g/- and was mostly amorphous. The glass transition temperature of this sheet was determined by DSC.
The temperature was 90°C when measured using a heating rate of 10°C/min. This unstretched sheet was heated to 3.5× at 94°C.
A film was obtained by simultaneous biaxial stretching of 3.5 times. The T- of this film was measured by DSC at a heating rate of 10°C/min and found to be 285°C. This film was heat-set at 295° C. for 20 seconds at a constant length, and then subjected to relaxation treatment at 250° C. for 20 seconds with a shrinkage rate of 5%.

The final film thickness was 33 microns. Moreover, the density was 1.366 g/-.

The tensile properties of this film were as follows.

Tensile squeeze (vertical/horizontal): 23/22 (Mutsu/J)F
-5411 (vertical/horizontal): 11/11 (k
g/w) Elongation (length/411): 62/63
(%) After this film was left in a relaxed state for 10 minutes in an atmosphere of 270° C., the tensile properties were measured before and after insertion, and the retention rate was determined as follows.

Tensile strength retention rate (vertical/horizontal): 85/83 (94)
F-5 retention rate (1/height: 91/90 (!1()) Elongation retention rate (vertical/horizontal): 110/112 (%)
Further, the heat shrinkage rate and solder heat resistance of the film were measured before being left in a relaxed state for 10 minutes in an atmosphere of 270°C, and the results were as shown in Table 1.

Table 1 This film has excellent dimensional stability during heating and is useful as a base film for flexible printed wiring boards.

Comparative Example 1 The film used in Example 1 before the cormorant fixation was heated at 250°C for 2 hours.
It was heat-set at a constant length for 0 seconds, and then relaxed at the same temperature for 720 seconds at a shrinkage rate of 5%. The tensile properties of this film were as follows.

Tensile strength (length/width>10/22 (eyelid/i>F-5 value (
Vertical/Horizontal): 10/10 (kJr/#) extension
Degree (vertical/horizontal): 6] 15B (%) After leaving this film in a relaxed state for 10 minutes in an atmosphere of 270°C,
The tensile properties were measured in the same manner as before, and the retention rates were determined as follows.

Tensile strength retention rate (1/horizontal): 47151 (%) F-
51 retention 1 ([/horizontal): 73/75 (%) Elongation retention (*/horizontal): 131/125 (%) Also, the film before being left in a relaxed state for 10 minutes in an atmosphere of 270°C The heat shrinkage rate and solder heat resistance were measured and were as shown in Table 2.

Table 2 13- Example 2 585 g of p-dichlorobenzene as 7-mer, 1,2
Polymerization was carried out under the same conditions as in Utility Model Application No. 1, except that 2.1 g of 4-trichlorobenzene was used, and a gray-white, granular polymer was obtained. The solution viscosity of this polymer was measured under the same conditions as in Example and found to be 0.42 a/g.

This polymer was formed into a film by pressing at 310°C, and then quenched in water to obtain a transparent unstretched sheet with a thickness of 400 microns.

The density of this sheet was measured], 322 g/cd
and was mostly amorphous. The glass transition temperature of this sheet was measured in the same manner as in Example 1 and was found to be 91°C. This unstretched sheet was heated to 3.5°C at 95°C.
A film was obtained by simultaneous biaxial stretching of 3.5 times. The T11 of this film was measured in the same manner as in Example 1 and was found to be 279°C. This film was heat-set at 305° C. for 20 seconds at a constant length, and then subjected to relaxation treatment at 260° C. for 15 seconds with a shrinkage rate of 5%. The thickness of the final d film is approximately 3
3 microns, and the density was 1.364 g/-.

The results of the tensile properties of this film are shown below.

Pull 41 strength (1/horizontal): I 9/20 (k
g/l1m1) F-5 value (1/horizontal): 10/
10 (kit/w') Elongation (vertical/horizontal): 58
157 (%) This film was heated in an atmosphere of 270°C.
After being left in the relaxed state for 0 minutes, the tensile properties were measured in the same manner and the retention rate was determined as follows.

Tensile strength retention rate (vertical/horizontal): 86/85 (%) F-5
Value retention rate (*/411): 95/93 (%) Elongation retention rate (vl/horizontal): 109/111
(%) Also, when we measured the heat shrinkage rate and solder heat resistance of the film before leaving it in a relaxed state for 10 minutes in an atmosphere at 270°C, the heat shrinkage rate at 250°C was 0.6%.
Furthermore, the shrinkage rate in one direction after immersion in solder at 260° C. for 30 seconds was 0.7%, indicating that the film of the present invention has excellent dimensional stability during heating.

Ratio 1!2 Example 2 The film used in Example 2 before heat setting was heated to 240°C.
It was heat-set for 0 seconds at a constant length, and then subjected to a relaxation treatment of 5% shrinkage at 250° C. for 15 seconds. The cliff in this film is 1
．． The results of the tensile properties of this film were 348 g/-.

Tensile strength (1/horizontal): 17/+8 (kg
/ town) F-5 value (vertical/horizontal): 10 / 10 (k
g/j) Elongation (N/lateral): 51/49 (%) After this film was left in a relaxed state for 10 minutes in an atmosphere at 270°C, the tensile properties were similarly measured and the retention rate was determined. The situation was as follows.

Tensile strength retention rate (vertical/horizontal): 53151 (%) F-
Five-value retention rate (length/width): 15/14 (%) Elongation retention rate (l/width) = 131/135 (%)
The heat shrinkage rate and solder heat resistance of the film were measured before being left in a relaxed state for 10 minutes in an atmosphere of 270°C.
The heat shrinkage rate at 250°C is 9.3%, and at 260°C,
The shrinkage rate in one direction after 30 seconds of solder immersion was 11%, and wrinkles occurred in the film. This film had poor thermal stability during heating and was unsuitable for use as a flexible printed wiring board that undergoes soldering.

Claims (1)

[Claims] A poly p-phenylene sulfide film containing 90 mol% or more of repeating units +S+, the solution viscosity of the polymer is 0.11//g or more, and a length of 10 m in the vertical and horizontal directions from the parenthesized film. 100-150
The tensile strength, stress at 5% elongation, and elongation values before the heat treatment when cut into 5 mm length, heat treated at 270°C for 10 minutes in a relaxed state, and then elongated at 23°C at a rate of 200%/min. Tensile strength and elongation of 5% when the film is stretched under the above conditions
Comparing the stress and elongation values at 60 and above, respectively,
A biaxially oriented poly p-phenylene sulfide film having a retention rate of 80% or more and 80 to 120%.