JP2001170991A - Apparatus and method for manufacturing polymer sheet, and polymer sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for continuously manufacturing a polymer sheet showing excellent surface smoothness and to provide a polymer sheet using the same. SOLUTION: The apparatus for manufacturing the polymer sheet is provided with an extruder, a T-die or a coat hanger die, an air floating bar making the polymer sheet melt-extruded from the T-die or the coat hanger die contact a take-up roll and the take-up roll wherein a clearance between the air floating bar and the take-up roll is within 50 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for efficiently producing a high heat-resistant polymer sheet having excellent smoothness, a method for producing the same, and a method for producing the same. It relates to the produced polymer sheet.

[0002]

2. Description of the Related Art In recent years, various sheets of a high heat-resistant polymer having a glass transition temperature (Tg) of 200 ° C. or higher have been used for electronic industrial applications. Of these applications, those used in glass plate replacement or metal plate replacement are required to have extremely good smoothness, that is, extremely small surface roughness, such as a substrate for a liquid crystal display element. There are uses. Conventionally, when producing a high heat-resistant polymer sheet with good smoothness, a solution of the high heat-resistant polymer is cast on a polished glass substrate or a polished steel belt, and the solvent is evaporated to obtain a film. The law is widely used. However, casting has a problem that it is difficult to obtain a film having a thickness exceeding 200 μm.

On the other hand, heat resistance is not so high, for example, T
For a polymer sheet having a g of 200 ° C. or less, a sheet is manufactured by an extrusion method using a T die or a coat hanger die. In general, if the polymer extruded from the die is taken directly by the take-off roll, the polymer is drawn in the tangential direction of the roll, so the gap (air gap) between the die and the contact with the roll becomes large, and the temperature increases. Because of the lowering, the transfer roll surface cannot be sufficiently transferred, and it is difficult to obtain a smooth surface. Therefore, with the extruded polymer at a temperature of Tg or higher,
By using a roll of an elastic material with low surface energy such as fluorinated rubber and pressing it against a take-off roll with a small surface roughness, the take-up roll surface is transferred to produce a sheet with a smooth surface. I have. However, Tg is 200
In the case of a high heat-resistant polymer having a temperature of 200 ° C. or higher, such a method cannot be performed because there is no roll of an elastic material having a low surface energy having a continuous use temperature of 200 ° C. or higher.

Further, as a method of bringing the extruded polymer into contact with the take-off roll with a short air gap without contact, a vacuum box system and an air knife system are used. In the vacuum box method, an enclosure is provided on the opposite side of the polymer sheet to be pulled by the take-up roll, and suction is performed to prevent the polymer from being drawn in the tangential direction of the roll. An air nozzle is installed on the side where the polymer sheet is pulled by the take-up roll and air is blown to prevent the polymer from being drawn in the tangential direction of the roll. However, in the vacuum box system, the temperature of the polymer drops due to the suction of ambient room temperature air, and the transfer of the take-up roll is not good, or foreign matter is mixed in because the surrounding dust is attracted. There are cases. On the other hand, in the air knife method, the temperature of the polymer can be prevented from lowering by using hot air. However, since the amount of air blown is remarkable, the polymer sheet may be shaken to cause uneven thickness or entrain the surrounding dust.

[0005]

An object of the present invention is to provide a method for efficiently producing a polymer sheet having excellent smoothness in the production of a polymer sheet. An object of the present invention is to efficiently manufacture and provide a heat-resistant polymer sheet having good smoothness.

[0006]

The present invention provides: Extruder, T-die or coated hanger die, chargeable air floating bar for bringing polymer sheet melt-extruded from T-die or coat hanger die to take-off roll, take-off roll, charged air floating bar and take-up roll 1. An apparatus for producing a polymer sheet having a gap of 50 mm or less, The maximum (Rmax) of the surface roughness of the take-up roll is 0.1
2. The apparatus for producing a polymer sheet according to item 1, which is not more than μm. 3. A method for producing a polymer sheet in which a polymer sheet melt-extruded from a T-die or a coat hanger die is brought into contact with a take-up roll by using a charged air floating bar that blows out gas; The temperature of the gas ejected from the charged air floating bar is equal to or higher than the glass transition temperature of the polymer.
4. The method for producing a polymer sheet according to the above item, 5. The method for producing a polymer sheet according to item 3 or 4, wherein the melt-extruded sheet is charged to a potential difference of 2 kV or more with a take-up roll by a voltage applied from a charging type air floating bar; 6. a polymer sheet manufactured using the polymer sheet manufacturing apparatus according to item 1 or 2; 7. A polymer sheet produced by using the method for producing a polymer sheet according to item 3, 4, or 5; Item 6 or Item 7 wherein the glass transition temperature is 200 ° C. or more and the maximum surface roughness (Rmax) is 0.1 μm or less.
Or the polymer sheet described above.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An apparatus for producing a polymer sheet according to the present invention is a charging type in which a polymer sheet melt-extruded from an extruder, a T-die or a coat hanger die, a T-die or a coat hanger die is brought into contact with a take-up roll. A polymer sheet manufacturing apparatus having an air floating bar and a take-up roll, wherein a gap between the charging type air floating bar and the take-up roll is within 50 mm. The charging type air floating bar in the present invention refers to a roll shape, a shape obtained by cutting a roll in half so as to form a semicircle, or a fan-shaped 1/3, 1
It is a device that has a shape divided into / 4, 1/6, etc., has many fine holes in its curved surface, and can blow air out of it, and can apply a high voltage to the bar itself. . As such an apparatus, a combination of an air floating bar, which is currently used as a turn bar in a polymer sheet conveying path, and a static electricity generator can be used. The curved surface portion having fine holes can be formed by making holes in the surface of the hollow roll or cutting a metal sintered body having voids. By providing a charging air floating bar between the T-die or coat hanger die and the take-up roll, the air gap can be reduced, and since the polymer sheet does not touch the surface of the charging air floating bar, it is heat resistant like a fluorinated rubber There is no problem of lack of sex.
Further, unlike the air knife, since the amount of the blown air is extremely small, the strong airflow does not adversely affect the sheet.

In the present invention, the gap between the charging type air floating bar and the take-up roll needs to be within 50 mm. If the gap is wider than this, the sheet does not adhere well to the take-off roll. Here, the gap between the charging air floating bar and the take-up roll is the shortest distance between the take-up roll surface closest to the charging air floating bar and a part (curved portion or corner portion) of the charging air floating bar. Refers to distance. Examples of the gas ejected from the charging type air floating bar used in the polymer sheet manufacturing apparatus of the present invention include air, nitrogen, and inert gas. The temperature of the gas is preferably equal to or higher than the glass transition point (Tg) of the polymer in order to facilitate adhesion to the take-up roll, and more preferably the same temperature as the T-die or the coat hanger die. The take-up roll used in the present invention has a maximum surface roughness Rm for obtaining a smooth sheet.
ax is preferably 0.1 μm or less. Where R
The max refers to a case where an arbitrary position on the roll surface is measured by scanning at a width of 1 mm. In the case of manufacturing a sheet having an uneven shape such as a prism sheet, it is also possible to transfer and form the sheet by using a roll having an uneven shape.

The polymer used in the polymer sheet of the present invention includes polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyethylene terephthalate,
Examples include, but are not limited to, polybutylene terephthalate, polyamide, polysulfone, polyethersulfone, polyetherimide, polyesterimide, polyetheretherketone, and the like. Among them, polyether sulfone, polyamide having an aromatic structure, and the like are preferable as sheets of optical materials and electronic industrial materials that require high heat resistance and surface smoothness because Tg exceeds 200 ° C.

[0010]

The present invention will be described below with reference to examples, comparative examples, and drawings, but the present invention is not limited to the examples. The optical properties of the sheet were measured by the following methods. (1) Sheet thickness 20 m in the width direction of the polymer sheet with a contact type dial gauge
Average value measured at m intervals. (2) Maximum surface roughness of polymer sheet (Rmax) Contact type precision step meter (manufactured by TENCOR INSTRUMENTS, AlPHA-ST)
EP200) is the maximum value of the concavities and convexities measured over the entire width of the polymer sheet at a scan width of 1 mm in the width direction. (3) Maximum surface roughness of the roll surface (Rmax) The maximum surface roughness when measuring the entire width of the roll with a cut-off length of 0.8 mm in the width direction of the roll using a contact surface roughness meter manufactured by Mitutoyo Corporation. value.

Example 1 As shown in FIG. 1, using a single screw extruder, a coat hanger die (1) having a die temperature of 370 ° C. and a polyether ether ketone (Tg: 143 ° C.) having a width of 800 mm and a die lip gap of 1 mm was used. )
Length of jetting air at 280 ° C at 7 m ³ / min 1
The melt-extruded sheet is charged to a potential difference of 3 kV with respect to the take-off roll while being held down by the charging air floating bar (2) of m, and the temperature at a position 40 mm away is controlled to 120 ° C. Rmax = 0.05 μm The take-up roll (3) on the surface of the hard chrome plating was used for take-up. The obtained sheet was subsequently cooled by a take-up roll (4) at a temperature of 40 ° C. and wound up to obtain a polymer sheet (5) having a thickness of 300 μm. When the surface roughness was measured, the Rmax of the polymer sheet was 0.05 μm. The film thickness unevenness excluding the ear portions at both ends was in the range of ± 20 μm.

Example 2 Polyether sulfone (Tg: 223 ° C.) at a die temperature of 360 ° C. using a single screw extruder
Is extruded from a coat hanger die having a width of 800 mm and a die lip of 1 mm, and nitrogen of 250 m ° C. is applied at 7 m ³ / mi.
n while charging with a 1 m long charging type air floating bar ejected with n, the melted and extruded sheet is charged to a potential difference of 10 kV with respect to a take-up roll, and 30 mm
Rmax where the remote temperature is controlled to 180 ° C =
The take-off was performed with a take-up roll having a hard chromium plating surface of 0.04 μm. The obtained sheet was subsequently cooled with a roll at a temperature of 40 ° C. and wound up to obtain a polymer sheet having a thickness of 200 μm. When the surface roughness was measured, the Rmax of the polymer sheet was 0.04 μm. The film thickness unevenness excluding the ear portions at both ends was in the range of ± 10 μm.

Example 3 Using a single screw extruder, polyetherimide (Tg: 216 ° C.) was extruded at a die temperature of 375 ° C. from a coat hanger die having a width of 800 mm and a die lip gap of 1 mm, and air at a temperature of 300 ° C. was 7 m ^3. / Min
The melt-extruded sheet was charged to a potential difference of 5 kV with respect to the take-up roll while being held down by a charging air floating bar having a length of 1 m, and the temperature at a position 50 mm away was controlled to 200 ° C., and Rmax = 0. .
The take-off was carried out with a take-up roll having a hard chrome plating surface of 07 μm. The obtained sheet was subsequently cooled with a roll at a temperature of 40 ° C. and wound up to obtain a polymer sheet having a thickness of 75 μm. When the surface roughness was measured, the Rm of the polymer sheet was measured.
ax was 0.07 μm. The film thickness unevenness excluding the ear portions at both ends was in the range of ± 6 μm.

Comparative Example 1 Using a single screw extruder at a die temperature of 370 ° C., polyether ether ketone (Tg: 14)
3 ° C.) was extruded from a coat hanger die having a width of 800 mm and a die lip gap of 1 mm, and a resin temperature of 280 ° C. was used to control the temperature to 120 ° C. using a 1 m long fluorinated rubber elastic roll. 05μm
When the nip was carried out by nipping the take-up roll on the surface of the hard chrome plating, the elastic roll made of fluorinated rubber was deteriorated by heat as the operation was continued.

Comparative Example 2 Polyethersulfone (Tg: 223 ° C.) at a die temperature of 360 ° C. using a single screw extruder
Was extruded from a coat hanger die having a width of 800 mm and a die lip of 1 mm, and the temperature at a position 30 mm away was controlled to 180 ° C. while controlling the resin temperature at 250 ° C. using a roll of hard chrome plating having a length of 1 m. When a take-up roll having a surface of 0.04 μm hard chrome plating was used to take off, polyether sulfone was wrapped around the roll used for holding, and a continuous sheet could not be obtained.

Comparative Example 3 Using a single screw extruder, polyetherimide (Tg: 216 ° C.) was extruded at a die temperature of 375 ° C. from a coat hanger die with a vacuum box having a width of 800 mm and a die lip gap of 1 mm, and extruded by vacuum suction. While attracting the polymer
Taking was performed with a take-up roll on the surface of hard chromium plating with Rmax = 0.07 μm controlled at 0 ° C. At this time, since the die hit the roll, the die lip could be approached to the take-up roll at a minimum distance of 120 mm. The obtained sheet was subsequently cooled with a roll at a temperature of 40 ° C. and wound up to obtain a polymer sheet having a thickness of 75 μm. When the surface roughness was measured, the Rm of the polymer sheet was measured.
ax was 0.20 μm.

[0017]

According to the manufacturing apparatus and the manufacturing method of the present invention, a high heat-resistant polymer sheet having good surface smoothness can be stably manufactured efficiently and continuously. The sheet obtained according to the present invention was not only locally small in maximum value of surface roughness but also small in thickness unevenness and excellent.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a manufacturing apparatus used in a first embodiment.

[Explanation of symbols]

 1: Coat hanger die 2: Charging type air floating bar 3: Take-up roll-1 4: Take-up roll-2 5: Polymer sheet 6: High voltage generator

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F207 AA04 AA11 AA15 AA24 AA28 AA29 AF14 AG01 AH33 AH73 AR12 KA01 KA17 KK56 KK66 KK90 KL84 KW21

Claims (8)

[Claims] An extruder, a T-die or a coat hanger die,
It has a chargeable air floating bar for bringing the polymer sheet melt-extruded from the T-die or coat hanger die into contact with the take-up roll, and a take-up roll, and the gap between the charge-type air floating bar and the take-up roll is within 50 mm. An apparatus for producing a polymer sheet. 2. The maximum surface roughness (Rmax) of a take-off roll.
2. The apparatus for producing a polymer sheet according to claim 1, wherein a is 0.1 μm or less. 3. A method for producing a polymer sheet, comprising: bringing a polymer sheet melt-extruded from a T-die or a coat hanger die into contact with a take-off roll using a charging type air floating bar for jetting gas. 4. The method for producing a polymer sheet according to claim 3, wherein the temperature of the gas ejected from the charging type air floating bar is higher than the glass transition temperature of the polymer. 5. The method for producing a polymer sheet according to claim 4, wherein the voltage applied from the charging type air floating bar charges the melt-extruded sheet to a potential difference of 2 kV or more from a take-up roll. 6. A polymer sheet produced using the apparatus for producing a polymer sheet according to claim 1. 7. A polymer sheet manufactured by using the method for manufacturing a polymer sheet according to claim 3, 4 or 5. 8. The polymer sheet according to claim 6, having a glass transition temperature of 200 ° C. or higher and a maximum surface roughness (Rmax) of 0.1 μm or less.