JPH0796703B2 - Vacuum deposition method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vacuum deposition method for a polyphenylene sulfide film.

[Prior Art] Japanese Laid-Open Patent Publication No. 60-255978 discloses that a polyphenylene sulfide film is vacuum-deposited with aluminum to form a metallized film, and that the metallized film is used for capacitors and the like. ing. It is also widely known to use a roll-up vacuum vapor deposition machine for the production of metallized films.

[Problems to be Solved by the Invention] However, conventionally, when metal deposition is performed on a polyphenylene sulfide film by a winding type vacuum deposition machine, wrinkles are likely to occur on the film on a cooling can of the deposition machine, and wrinkles are generated by latent heat of the evaporated metal. There is a drawback in that when fixed, the metallized film tends to have wrinkles and deteriorate in flatness (hereinafter sometimes referred to as "heat loss"). When attempting to manufacture a capacitor tape, etc. by cutting the metallized film in which this "heat loss" has occurred, the dimensional accuracy becomes poor, and for example, the width of the margin part (non-deposited part) fluctuates, causing capacitor failure. There is an adverse effect such as causing.

An object of the present invention is to eliminate the drawbacks that occur during the vacuum deposition of the conventional polyphenylene sulfide film as described above, and to provide a method for depositing a polyphenylene sulfide film that does not easily cause "heat loss" when performing metal deposition with a roll-up type vacuum deposition machine. To provide.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a method of vacuum-depositing a metal on at least one surface of a polyphenylene sulfide film by a winding-type vacuum vapor deposition machine, wherein the film has a long film length. 10 ℃ from 25 ℃ to 70 ℃ while applying tension of 3 kg per square millimeter in the cross direction
When a polyphenylene sulfide film having a longitudinal elongation of 0.4% or less when heated at a speed of 1 / min is used, and the average longitudinal tension of the film on the cooling can of the vapor deposition machine is 1 0.5 per square millimeter
It is a vacuum deposition method for a polyphenylene sulfide film, which is characterized in that the weight is about 3 kg.

In the present invention, the polyphenylene sulfide film (hereinafter sometimes abbreviated as PPS film) is a biaxially oriented film of a resin composition containing poly-p-phenylene sulfide as a main component. The thickness of the film is 0.
It is in the range of 4 to 25 μm, but the effect is large in the range of 0.4 to 10 μm. The average surface roughness Ra of the film is 0.03 from the viewpoint of workability during winding and adhesion during heating and pressing after winding.
The range of ~ 0.10 is preferred. Further, it is preferably a crystallized film having a crystallinity of 25% to 45% by X-ray diffractometry.
Furthermore, the degree of orientation OF obtained for the crystal peak at 2θ = 20 to 21 ° C by wide-angle X-ray diffraction is 0.07 in the End direction and Edge direction.
It is preferable that the biaxially oriented film is in the range of 0.5 to 0.5 and 0.6 to 1.0 in the Through direction.

Here, a resin composition containing poly-p-phenylene sulfide as a main component (hereinafter, may be abbreviated as a PPS-based composition) means 70% by weight of poly-p-phenylene sulfide.
A composition containing the above. When the content of poly-p-phenylene sulfide is less than 70% by weight, the crystallinity of the composition, the heat transition temperature and the like are lowered, and the heat resistance, dimensional stability and mechanical properties which are the features of the film made of the composition are low. Impair the characteristics. The remaining less than 30% by weight in the composition may contain additives such as polymers other than poly-p-phenylene sulfide, inorganic or organic fillers, lubricants, colorants, and UV absorbers. The melt viscosity of the resin composition is preferably in the range of 500 to 12000 poise (more preferably 700 to 10000 poise) at a temperature of 300 ° C. and a shear rate of 2001 / sec from the viewpoint of film formability. The melt viscosity of the resin composition is equal to the melt viscosity of the polyphenylene sulfide film finally obtained.

In the present invention, poly-p-phenylene sulfide (hereinafter sometimes abbreviated as PPS) means a repeating unit of 7
0 mol% or more (preferably 85 mol% or more) is the structural formula A polymer comprising a structural unit represented by Related ingredients
If it is less than 70 mol%, the crystallinity of the polymer, the heat transition temperature, etc. are lowered, and the heat resistance, dimensional stability, mechanical properties, etc., which are the features of the film made of the resin composition containing PPS as a main component, are impaired.

If the repeating unit is less than 30 mol%, preferably less than 15 mol%, a unit containing a copolymerizable sulfide bond may be contained.

In addition, it is preferable that the film of the present invention contains inorganic fine particles for the purpose of adjusting the surface roughness.

In the present invention, 25 ° C. to 70 ° C. is applied while applying a tension of 3 kg per 1 mm 2 in the longitudinal direction of the film.
Elongation in the longitudinal direction when the temperature is raised up to 10 ° C / min
It is necessary to use a polyphenylene sulfide film that is 0.4% or less. When the elongation exceeds 0.4%, the above-mentioned "heat loss" is likely to occur during vacuum deposition, and the object of the present invention cannot be achieved. The magnitude of such elongation is preferably 0.3% or less. Further, it is preferable that the elongation when heated to 50 ° C. under the same conditions is 0.15% or less. Further, it is more preferable that the elongation when heated to 80 ° C. under the same conditions is 0.4% or less.

The method for controlling the elongation of the polyphenylene sulfide film to fall within the above range is not particularly limited.
A resin composition containing poly-p-phenylene sulfide as a main component by a well-known method described in 111235 and the like is supplied to an extruder and melted, and extruded from a T die onto a cooling drum to form a non-oriented sheet, The sheet is biaxially stretched vertically or horizontally at a temperature of 95 to 115 ° C, or sequentially at 200 ° C.
As mentioned above, there may be mentioned a method in which the intermediate is obtained by heat treatment at a temperature equal to or lower than the melting point, and then the intermediate is heat-treated at 30 to 120 ° C. (preferably 30 to 70 ° C.) for 5 seconds to 10 days. The time of the heat treatment can be appropriately selected depending on the temperature. Generally, it takes a long time at a low temperature and a short time at a high temperature. The heat treatment can be carried out continuously with the production of the intermediate in the film production line, or can be carried out once after being wound. In the latter case, it can be carried out continuously while unwinding the film, or can be carried out by putting it in a hot air oven in a roll form. Further, the heat treatment can be performed in two or more steps at different temperatures.

A metal is vacuum-deposited on at least one surface of the film by a continuous winding type vapor deposition machine. At this time, the average tension in the longitudinal direction of the film on the cooling can of the vapor deposition machine must be 0.5 to 3 kg per 1 mm 2 of the cross-sectional area of the film. If the tension is too low or too high, heat winding tends to occur. Here, the average longitudinal tension of the film on the cooling can refers to the arithmetic average value of the longitudinal tension immediately before the film contacts the cooling can and the longitudinal tension immediately after leaving the cooling can. In the vapor deposition machine provided with two cooling cans for continuously vapor-depositing both sides of the film, it is necessary to satisfy the above tension condition for each cooling can.

The temperature of the refrigerant circulating in the cooling can is preferably -15 ° C or lower in order to reduce heat loss.

Regarding the metal to be vacuum-deposited, regardless of its type,
Examples include aluminum, zinc, tin, copper, gold and silver.
Further, the method of heating the metal to be vacuum-deposited is not particularly limited, such as the resistance heating method and the electron beam heating method.

[Characteristic Measuring Method and Evaluation Method] (1) Elongation S ₇₀ (or S ₅₀ , S ₈₀ ) In the present invention, 25 ° C. to 70 ° C. while applying a tension of 3 kg per 1 mm 2 of the cross-sectional area in the longitudinal direction of the film.
(Or 50 ° C. or 80 ° C.) When measuring the elongation in the longitudinal direction when the temperature is raised at a rate of 10 ° C./minute, a test piece with a length of 1100 mm and a width of 10 mm is cut out in the longitudinal direction of the film, and A load equivalent to 3 kg per square mm of the test piece was attached to the lower end and hung in a hot air oven that kept the temperature at 25 ° C. The interval L ₀ is read by two optical position detectors (line sensors), and the temperature of the hot air oven is raised at a rate of 10 ° C / min and reaches the temperature of 70 ° C (or 50 ° C or 80 ° C) Re-read the interval L between the marked lines of 100x (L-L ₀ )
/ L ₀ (unit%), elongation S ₇₀ (or S ₅₀ or S
₈₀ ) is calculated.

(2) Degree of "heat loss" during vapor deposition Aluminum was vapor-deposited on a film sample having a width of 500 mm using a continuous winding single-sided vapor deposition machine manufactured by Nippon Vacuum Giken Co., Ltd. At this time, the temperature of the refrigerant circulated in the cooling can was set to −30 ° C., and vapor deposition was performed in stripes in which vapor deposition portions of 9 mm width and non-vapor deposition portions of 1 mm width were alternately repeated.

The metallized film was observed after vapor deposition and the degree of "heat loss" was determined according to the following criteria.

◯: Wrinkles of ten or less lines running in the longitudinal direction of the metallized film are seen, but the other portions have good flatness.

Δ: In addition to a dozen or more wrinkles running in the longitudinal direction of the metallized film, undulations are seen throughout, but wrinkles disappear while tension is applied.

X: In addition to a dozen or more wrinkles running in the lengthwise direction of the metallized film, waviness is seen throughout, and wrinkles remain even when tension is applied.

EFFECTS OF THE INVENTION The vacuum vapor deposition method of the present invention has the above-mentioned configuration, and thus has a drawback of "heat loss" during vapor deposition, which has been a drawback when vacuum-depositing a metal on a polyphenylene sulfide film by a winding vapor deposition machine. Is less likely to occur, and as a result, dimensional accuracy is improved when the resulting metallized film is cut into a capacitor tape, and the defective rate of the capacitor is reduced. Further, even when the obtained metallized film is coated for the purpose of manufacturing a so-called lacquer coating type multilayer capacitor, there is an effect that a dimensional deviation from the coating pattern hardly occurs.

[Operation] It is not clear why the vacuum vapor deposition method of the present invention makes it difficult to cause "heat loss" during vapor deposition, but if the elongation in the longitudinal direction of the film as described in the present invention is large, the film will be above the cooling can during vapor deposition. When passing, the film stretches due to the tension applied to the film and wrinkles, making contact with the cooling can worse, and when metal vapor flies on it, the condensation latent heat cannot escape to the can, causing film deformation due to heat. On the other hand, when the elongation in the longitudinal direction of the film in the present invention is small, such a phenomenon is unlikely to occur.

[Examples] Next, examples of the present invention will be described in more detail.

Example 1 (1) Production of PPS-BO used in the present invention In an autoclave, 32.6 kg of sodium sulfide (250 mol,
(Including 40% by weight of water of crystallization), 100 g of sodium hydroxide, 36.1 kg (250 mol) of sodium benzoate, and N-methyl-2.
-Pyrrolidone (hereinafter sometimes referred to as NMP) 79.2 kg
Was charged and dehydrated at 205 ° C., then 37.5 kg (255 mol) of 1,4 dichlorobenzene (abbreviated as p-DCB), and NMP20.
0 kg was added, and the mixture was reacted at 265 ° C for 4 hours. The reaction product was washed with water and dried to obtain 21.1 kg (yield 78%) of poly-p-phenylene sulfide consisting of 100 mol% of p-phenylene sulfide and having a melt viscosity of 3100 poise.

To this composition, 0.1 wt. Of fine silica powder with an average particle size of 0.7 μm
%, Calcium stearate 0.05% by weight, melted at 310 ° C. with a 40 mm diameter extruder, filtered with a 95% cut hole diameter 10 μm filter using metal fiber, and then a linear lip with a length of 400 mm and a gap of 1.5 mm was formed. It was extruded from the T-die and cast on a metal drum whose surface was kept at 25 ° C. to be cooled and solidified to obtain an unstretched film having a thickness of about 20 μm.

This film is stretched by a machine comprising a group of rolls,
The film was drawn at a temperature of 100 ° C and a draw speed of 30000% / min by a factor of 3.6, and then using a tenter, the temperature was 100 ° C and the draw speed was 1000.
The film was stretched 3.5 times at 3.5% / min, and further heat-treated under tension in a subsequent heat treatment chamber in the same tenter at 270 ° C. for 10 seconds to obtain an intermediate body (intermediate body-1) having a thickness of 2 μm.

The intermediate was wound into a roll and the roll was heat-treated in an oven at 50 ° C. for 72 hours to obtain a polyphenylene sulfide film (Film-1). The “elongation” S ₇₀ in the present invention of the film was 0.24%, which satisfied the conditions of the film used in the present invention.

Aluminum was vapor-deposited on this film-1 by using a continuous winding type single-sided vapor deposition machine manufactured by Nippon Vacuum Giken Co., Ltd. on a film sample having a width of 500 mm. At this time, the temperature of the refrigerant circulated in the cooling can was set to −30 ° C., and vapor deposition was performed in stripes in which vapor deposition portions of 9 mm width and non-vapor deposition portions of 1 mm width were alternately repeated. At this time, change the average tension on the cooling can as shown in Table-1,
It vapor-deposited on various conditions and obtained five kinds of metallized PPS films. From Table 1, it can be seen that the "heat loss" is significantly improved when the film defined in the present invention is vapor-deposited under the conditions of the present invention.

Example 2 The intermediate body 1 obtained in Example 1 was wound into a roll, and heat-treated in the same manner as in Example 1 while appropriately changing the temperature and time of heat treatment, and then in the longitudinal direction of the film according to the present invention. 25 ℃ to 70 ℃ while applying tension of 3 kg per 1 square millimeter
Elongation S in the longitudinal direction when the temperature is raised up to 10 ° C / min
Five types of ₇₀ different films (Film-2 to Film-6) were obtained. Aluminum was vacuum-deposited on these films in the same manner as in Example 1 under plane tension on a cooling can as shown in Table 2. The evaluation results are shown in Table-2.
From Table 2, it can be seen that when the vapor deposition is performed by the method of the present invention, "heat loss" during vapor deposition hardly occurs.

Claims (1)

[Claims] 1. A method of vacuum-depositing a metal on at least one surface of a polyphenylene sulfide film by a winding-type vacuum vapor deposition machine, wherein a tension of 3 kg per 1 mm 2 is applied in the longitudinal direction of the film as the film. Longitudinal average tension of the film on a cooling can of a vapor deposition machine, using a polyphenylene sulfide film that has a longitudinal elongation of 0.4% or less when heated from 10 to 70 ° C at a rate of 10 ° C / min. Is 0.5 to 3 kg per 1 mm 2 of the cross-sectional area of the film, the method for vacuum deposition of a polyphenylene sulfide film.