JP2001353767A - Method for producing polycarbonate resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stably producing a polycarbonate resin film which contains powder and is excellent in lubricity. SOLUTION: In the method for producing the polycarbonate resin film in which the polycarbonate resin film containing the powder is melt-extruded from a T-die lip and taken up by a cooling roll, only the surfaces of both end parts of the cooling roll are roughened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polycarbonate resin film. More specifically, the present invention relates to a production method capable of stably producing a polycarbonate resin film having excellent lubricity.

[0002]

2. Description of the Related Art Polycarbonate resin films are widely used in various fields because of their excellent properties, and are also used as films. Printing and other processes are also performed on polycarbonate resin films.
2. Description of the Related Art In recent years, the processing speed has been increased with the progress of processing technology such as printing. However, the polycarbonate resin film has a drawback that it has poor lubricity and its surface is easily adhered, which is a bottleneck in processing.

Hitherto, a method of roughening the surface of a sheet has been proposed to improve the lubricity of a synthetic resin film. For example, a method of roughening one or both sides of a melt-extruded film using a roughened cooling roll (Japanese Patent Application Laid-Open No. 64-72831), a method of kneading inorganic or organic powder to roughen the surface. Method (Japanese Patent Application Laid-Open No. 53-140343)
And Japanese Patent Application Laid-Open No. 55-11142 are known.

However, in the former method, it is necessary to newly install a roughened cooling roll and guide roll, and it is necessary to replace the roll when the nameplate is switched, which leads to a complicated operation and an increase in cost.

In the latter method, when a film applied to a polycarbonate resin film and melt-extruded is sandwiched between a pair of cooling rolls and pressed against both sides, a part of the kneaded powder emerges on the surface of the film. Further, there is a disadvantage that the film is laterally shifted on the surface of the cooling roll in contact with the cooling roll, and the end face of the wound film is shifted.

As a solution to this problem, a method of electrostatically adhering a film to a roll by using a high voltage, a method of obtaining a roughened sheet by thickening only both end portions of the sheet and contacting a cooling roll (Japanese Patent Application Laid-Open No. Hei 5-338011) Is known. However, in the former method, there is concern about safety, and more expensive equipment is required.

Further, the thickness of both ends of the latter film is extruded to be larger than the thickness of the other portions of the film, and only the both ends are sandwiched by the cooling rolls, and simultaneously, one side of the film other than the both ends is cooled. When it comes into contact with the film, it becomes difficult for the film to meander in the section until the film coming out of the cooling roll is taken up by the take-up roll, but it cannot be said that it is sufficient. May degrade value. Further, since the thickness of the film at both ends is increased, there is a disadvantage that the product yield of the film is reduced.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for stably producing a polycarbonate resin film containing powder and having excellent lubricity. The present inventor has conducted intensive studies to achieve the above object,
When the polycarbonate resin containing powder is melt-extruded from a T-die lip into a film, by preliminarily roughening the ends of the cooling roll, that is, the ends of the cooling roll where the lugs of the film are in contact. The present inventors have found that lateral displacement of the film is prevented, and that the film is prevented from being rolled, and the present invention has been achieved.

[0009]

According to the present invention, there is provided a method for producing a polycarbonate resin film by taking a polycarbonate resin film containing a powder melt-extruded from a T-die lip by a cooling roll. A method for producing a polycarbonate resin film, characterized by using a cooling roll having only roughened end portions.

The present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an apparatus for manufacturing a polycarbonate resin film, and FIGS. 2 and 3 are cross-sectional views showing a state where the polycarbonate resin film in FIG. 1 is sandwiched between cooling rolls. In the figure, 1 is a T-die lip, 2 is a melt-extruded polycarbonate resin film, 2 'is an edge portion of the film, 3, 4 and 5 are cooling rolls, 4' and 5 'are cooling rolls of a roughened portion, 6 is a take-up roll, 7 is a rolled film, and 8 is a paper tube.

In the present invention, as shown in FIG. 2 or FIG. 3, the edge of the film is sandwiched by the roughened portions (4 ', 5') at the ends of the cooling rolls 4 and 5. .

The roughened portion of the cooling roll referred to in the present invention is the width direction of the extruded film which is called the edge of the normal film shown by 4 'and 5' in FIGS. At both ends. The surface roughening is preferably performed on both the cooling rolls 4 and 5 as shown in FIG.
As shown in FIG. 3, only one of the cooling rolls may be used.

The width of the film is determined by the width of the T-die lip, and the portion corresponding to the edge of the film usually has a width of about 10 to 200 mm from the end of the T-die lip. Therefore, it is preferable that the position of the portion to be roughened is a cooling roll portion corresponding to a distance of 100 mm inward from both ends of the T-die lip. The width of the roughened portion may be equal to or less than the width of the edge of the film.
It is preferably from 100 to 100 mm, more preferably from 5 to 50 mm.

The surface of the part where the cooling roll is roughened may be any shape having irregularities such as a mat pattern, an embossed pattern or a ridge shape. Any shape with no resistance is acceptable.

The width and depth of the irregularities in the portion where the cooling roll is roughened are not specified as long as they are within the range that can correspond to the thickness of the film. In the present invention, the thickness of the polycarbonate resin film is 100 to 100. 500 μm is preferable, and the depth of the unevenness of the roughened portion of the cooling roll is 1
The width is preferably from about 0 to 150 μm and the width is preferably from about 10 to 150 μm, and more preferably the depth is from about 50 to 100 μm and the width is from about 50 to 100 μm.

In the present invention, a method for producing a polycarbonate resin film having excellent lubricity is, specifically, kneading and melting a polycarbonate resin in which a predetermined amount of powder is dispersed by a T-die extruder and passing through a T-die lip. It is manufactured by a method of taking out the extruded molten polycarbonate resin while cooling it with a cooling roll. The temperature of the cooling roll is 1
It is preferable to set the temperature to 00 to 160 ° C. At this time, when the polycarbonate resin film is sandwiched between the roughened portions of the cooling roll, the roughened portions (4 ′, 5 ′)
Since the polycarbonate resin film is buried in the film, lateral displacement of the film generated on the cooling roll is prevented.

If the polycarbonate resin film produced in the present invention is too thin, it will be buried in the roughened portion of the roll, and if it is too thick, it may be difficult to wind it. The thickness is about 100 to 500 μm. Is preferred. Further, the polycarbonate resin film having excellent lubricity targeted in the present invention has a surface roughness of 0.0
The range is preferably from 5 to 20 μm, more preferably from 0.05 to 5 μm, even more preferably from 0.1 to 1 μm.

The cooling roll used in the present invention, in which only the end of the cooling roll is roughened, can be used as it is as a mirror-finished roll used in the production of ordinary polycarbonate resin films. Further, the material of the roll may be arbitrarily determined, and the diameter thereof is determined as appropriate.

The polycarbonate resin used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor by an interfacial polycondensation method or a melting method. Representative examples of dihydric phenols include 2,2-bis (4-
Hydroxyphenyl) propane [commonly known as bisphenol A], 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-methyl-4-hydroxyphenyl) ) Propane, 2,2-bis (3,5-dimethyl-)
Examples thereof include 4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, and bis (4-hydroxyphenyl) sulfone. Of these, bisphenol A is preferable. These dihydric phenols can be used alone or in combination of two or more.

As the carbonate precursor, carbonyl halide, carbonate ester, haloformate and the like are used, and specific examples include phosgene, diphenyl carbonate and dihaloformate of dihydric phenol.

In producing the polycarbonate resin by reacting the dihydric phenol with the carbonate precursor by an interfacial polycondensation method or a melting method, if necessary, a catalyst, a terminal stopper and an antioxidant for the dihydric phenol may be used. Etc. may be used. Further, the polycarbonate resin may be a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin obtained by copolymerizing an aromatic or aliphatic bifunctional carboxylic acid, In addition, 2 of the obtained polycarbonate resin
It may be a mixture of more than one species.

The molecular weight of the polycarbonate resin is preferably 10,000 to 100,000, more preferably 15,000 to 35,000 in terms of viscosity average molecular weight (M). Polycarbonate resin having such a viscosity average molecular weight,
Sufficient strength is obtained, and the melt fluidity during molding is also favorable, which is preferable. The viscosity average molecular weight referred to in the present invention is 2 g of polycarbonate resin 0.7 g in 100 ml of methylene chloride.
The specific viscosity (η _sp ) obtained from the solution dissolved at 0 ° C. was obtained by inserting it into the following equation. η _sp /c=[η]+0.45×[η] ² c (where [η]
Is the intrinsic viscosity) [η] = 1.23 × 10 ⁻⁴ M ^0.83 c = 0.7

The powder to be blended with the polycarbonate resin film in the present invention may be any powder that roughens the film and imparts lubricity and does not adversely affect the polycarbonate resin, such as clay, kaolin, Silica-alumina clay minerals represented by calcined kaolin, silica-magnesium clay minerals represented by talc, inorganic powders such as calcium silicate, silica, alumina, calcium carbonate, barium carbonate, titanium oxide, glass powder, acrylate And organic powders such as a crosslinked polymer or a crosslinked copolymer such as styrene, acrylate-styrene and the like. Among them, calcium carbonate and a crosslinked acrylate polymer are preferably used.

The size of the powder is appropriately selected according to the desired degree of roughness of the film surface.
It is preferably about 0 μm, and the compounding amount is preferably in the range of 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the polycarbonate resin.

The polycarbonate resin film of the present invention may further comprise, if necessary, other components such as phosphorous acid, phosphoric acid, phosphite, phosphate, etc.
Heat stabilizers such as phosphonates, UV absorbers such as triazoles, acetophenones, and salicylates, flame retardants such as tetrabromobisphenol A, low-molecular-weight polycarbonates of tetrabromobisphenol A, and decabromodiphenylene ether, and trioxide Additives such as flame retardant aids such as antimony may be blended.

[0026]

EXAMPLES The present invention will be further described below with reference to examples. In addition,
Parts in Examples are parts by weight, and the evaluation was made by the following method. (1) Shape of rolled film: The film coming out of the cooling roll was taken up by a take-up roll, and this film was wound up continuously for 500 m around a paper tube (outer diameter: 6 inches) of a winder. A rolled film having a winding deviation of 20 mm or less at the end of the wound film (see FIG. 4) is indicated by “○”, and a winding film having a winding deviation of more than 20 mm (see FIG. 5) is indicated by “x”. (2) Surface roughness Ra (μm): JIS B-0610
The values measured by a stylus-type surface roughness meter [manufactured by Tokyo Seimitsu Co., Ltd.] are shown in accordance with Table 1. The cutoff is 2.5 mm and the measurement length is 8 mm.

Example 1 A polycarbonate resin film was manufactured using a T-die extruder equipped with the apparatus shown in FIG. 1200mm wide T-die lip and 300m diameter
m, a mirror-surface cooling roll having a width of 1650 mm was used. The surface roughening was performed on both the cooling rolls 4 and 5 at positions 240 to 255 mm from both ends of the roll as shown in FIG. 2 (the width of the roughened portion was 15 mm, and the depth of the unevenness of the roughened portion was 15 mm). 5
0 μm and width 50 μm).

Polycarbonate resin 1 having a viscosity average molecular weight of 24,500 prepared from bisphenol A and phosgene
After adding and mixing 1.0 part of powder A shown in Table 1 to 00 parts,
Cylinder temperature 290 ° C, discharge amount from T-die lip 1
Extruded into a film at 50 kg / hr (cooling roll 3
The cooling roll 4 is contact-cooled only on one side of the sheet, and both ends of the film, that is, the lugs are sandwiched between the rolls according to the roughened portions of the pair of cooling rolls 4 and 5, and the film is cooled. Without sagging, a film having a width of 1050 mm and a thickness of 130 μm was obtained. The temperatures of the cooling rolls 4 and 5 were set to 130 ° C. and 115 ° C., respectively. Table 1 shows the evaluation results.

Example 2 A film having a thickness of 400 μm was obtained in the same manner as in Example 1 except that the depth of the unevenness of the roughened portions of the cooling rolls 4 and 5 was 100 μm and the width was 100 μm. Table 1 shows the evaluation results.

Example 3 The width of the roughened portions of the cooling rolls 4 and 5 was 10 mm, and the depth of the irregularities of the roughened portions was 50 μm.
A film having a thickness of 130 μm was obtained in the same manner as in Example 1, except that the width was set to 100 μm. Table 1 shows the evaluation results.

Example 4 The width of the roughened portions of the cooling rolls 4 and 5 was 30 mm, and the depth of the irregularities of the roughened portions was 50 μm.
A film having a thickness of 400 μm was obtained in the same manner as in Example 1 except that the width was set to 100 μm. Table 1 shows the evaluation results.

Example 5 A film having a thickness of 130 μm was obtained in the same manner as in Example 3 except that 1.0 part of powder A was used instead of 1.0 part of powder A. Table 1 shows the evaluation results.

Example 6 The surfaces of the sheet were contact-cooled by the cooling rolls 3 and 4, and the temperatures of the cooling rolls 3, 4 and 5 were set to 120 ° C., 130 ° C. and 115 ° C., respectively.
A film having a thickness of 130 μm was obtained in the same manner as in Example 1, except that 1.0 part of powder B was used instead of 0 part. Table 1 shows the evaluation results.

Example 7 A film having a thickness of 400 μm was obtained in the same manner as in Example 6, except that the depth of the unevenness of the roughened portions of the cooling rolls 4 and 5 was 100 μm and the width was 100 μm. Table 1 shows the evaluation results.

Example 8 As shown in FIG. 3, only the cooling roll 4 was roughened (the width of the roughened portion was 15 mm, the depth of the unevenness of the roughened portion was 50 μm and the width was 50 μm). A film having a thickness of 130 μm was obtained in the same manner as described above. Table 1 shows the evaluation results.

Example 9 A film having a thickness of 400 μm was obtained in the same manner as in Example 8, except that the discharge amount of the polycarbonate resin was changed. Table 1 shows the evaluation results.

Comparative Example 1 A polycarbonate resin film was manufactured in the same manner as in Example 1 except that all of the cooling rolls 4 and 5 were mirror-finished rolls. Meandering between them, and stable production was not possible. Table 1 shows the evaluation results. The powders A and B used in Table 1 are as follows. Powder A: calcium carbonate having an average diameter of 5 μm [Cipron A manufactured by Cipro Kasei Co., Ltd.] Powder B: crosslinked acrylate polymer having an average diameter of 20 μm [MBX-20 manufactured by Sekisui Plastics Co., Ltd.]

[0038]

[Table 1]

[0039]

According to the method of the present invention, the end of the existing cooling roll is roughened to obtain a film having excellent lubricity.
A polycarbonate resin film with a uniform winding shape can be stably produced, and the obtained polycarbonate resin film is used as a display plate for automobiles, home appliances, OA equipment, vending machines, etc., a membrane switch, a film for insert molding, It is suitably used for printing on nameplates and the like, and the effect thereof is outstanding.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for producing a polycarbonate resin film used in the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of a state in which a polycarbonate resin film is sandwiched between roughened cooling rolls.

FIG. 3 is a cross-sectional view showing one embodiment of a state in which a polycarbonate resin film is sandwiched between roughened cooling rolls.

FIG. 4 is a cross-sectional view (example) showing a wound state of a wound polycarbonate resin film.

FIG. 5 is a cross-sectional view (comparative example) showing a wound state of a wound polycarbonate resin film.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 T die lip 2 melt-extruded polycarbonate resin film 2 ′ ear portion of polycarbonate resin film sandwiched between roughened cooling rolls 3 cooling roll 4 cooling roll 4 ′ cooling roll of roughened part 5 cooling roll 5 'Cooling roll of roughened portion 6 Take-up roll 7 Rolled-up polycarbonate resin film 8 Paper tube

Claims (1)

[Claims] 1. A method for producing a polycarbonate resin film by melt-extruding a polycarbonate resin film containing a powder from a T-die lip and picking up the polycarbonate resin film with a cooling roll, wherein a cooling roll having only both ends of the cooling roll roughened is used. A method for producing a polycarbonate resin film, which is used.