JPH09207210A - Film manufacturing device and manufacture of film using this device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface flawless film without allowing an oligomer to stick to the surface of a drum or a roll by using the drum or the roll which has a chrome plating film containing a specified number of carbon atoms for a chromium atom formed on the surface whose outer peripheral face has a specific surface roughness. SOLUTION: A film manufacturing drum or roll is used which has an outer peripheral face with a surface roughness of 1S or less and also a chrome plating film containing 0.5-5% of a carbon atom in terms of the number of atoms for a chromium atom formed on the surface. An oligomer is prevented from sticking to the drum or the roll by meeting both surface roughness and surface film composition conditions. If this plating film thickness is too small, the pliability of a foundation metal influences the thickness. On the other hand, if the thickness is too large, cracks are generated due to heat or stress strain. The recommended foundation metal on which the film is applied is normally SUS or carbon steel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film manufacturing method and a film manufacturing apparatus, and more particularly, to an excellent film which does not suffer from defects such as adhesion of oligomers existing in a polymer and scratches on the film surface caused by the adhesion. TECHNICAL FIELD The present invention relates to a method for manufacturing a metal and a manufacturing apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, when a molten polymer is extruded from a die and then stretched to form a film, the molten polymer extruded from the die is called a casting drum in order to obtain good flatness of the film. It is used as an industrial method in which the film is preheated to a predetermined temperature while running in contact with a roll, stretched and cooled, and the metal surface is hard chrome plated on such a casting drum or roll. I used the one coated with. However, in the conventional method, the oligomer (low polymer) present in the polymer is deposited on the surface during film production, adheres to the surface of the casting drum or roll described above, and the adhered matter is transferred onto the film, Scratches and digging scratches will occur due to this deposit,
This is a surface defect of the film, which is a problem in that a recording dropout occurs in magnetic recording applications, and an optical defect occurs in optical applications. Conventionally, trial and error has been added to avoid this, but there is no fundamentally good method, and it is said that the surface of the casting drum or roll is regularly polished and washed to remove deposits and produce. The method is general, and it is impossible to carry out production for a long time by this method, and there is a drawback that productivity is lowered.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. Specifically, the oligomer (low polymer) present in the polymer is cast during film production. It is an object of the present invention to provide a film manufacturing method and a film manufacturing apparatus capable of manufacturing a film for a long time without being attached to the surface of a drum or a roll.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that if a casting drum or roll that comes into contact with the film during the production of the film is made of a specific material, such a problem occurs. Solve the problem,
The inventors of the present invention have found that a film having no surface defects as described above can be produced, and have reached the present invention.

That is, the outer peripheral surface has a surface roughness of 1 S or less,
Further, the film manufacturing apparatus is characterized by using a film-manufacturing drum or roll having a chromium plating film containing 0.5 to 5% of carbon atoms with respect to chromium atoms as the number of atoms. Furthermore, when a molten polymer is extruded from a die and then stretched to form a film, at least one drum or roll in contact with the film has a surface roughness of 1 S or less and a carbon atom with respect to a chromium atom on the surface. 0.5 to the number of atoms
A method for producing a film, which comprises using a film-producing drum or roll having a chrome-plated coating containing 5% of the film.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The molten polymer in the present invention means a thermoplastic resin which is plastically fluidized by heating to a temperature above its melting point to bring it into a molten state, and such a thermoplastic resin is not particularly limited. Typical examples thereof include polyesters, polyamides, polyolefins, polystyrenes, polycarbonates, polyacrylonitriles, polyvinyl alcohols, polyphenylene sulfides, polyacetals, polyethers, and copolymers thereof. Further, two or more kinds of these thermoplastic resins may be blended.

Of these, polyesters, polyamides and copolymers thereof are preferred, and polyesters and copolymers thereof are more preferred.

The term "polyester" as used herein refers to a polyester containing an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid and a diol as main constituent components. As the aromatic dicarboxylic acid component, for example, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid,
1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid,
4,4′-diphenyl ether dicarboxylic acid, 4,4 ′
-Diphenyl sulfone dicarboxylic acid and the like can be mentioned, among which terephthalic acid, isophthalic acid,
2,6-naphthalenedicarboxylic acid and the like can be mentioned. Examples of the aliphatic dicarboxylic acid component include adipic acid, suberic acid, sebacic acid, dodecanedioic acid and the like. Moreover, as an alicyclic dicarboxylic acid component, 1,4-cyclohexane dicarboxylic acid etc. can be mentioned, for example. These acid components may be used alone or in combination of two or more, and may be partially copolymerized with an oxy acid such as hydroxybenzoic acid. Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2'-bis (4 ' Examples include -β-hydroxyethoxyphenyl) propane and the like. Among them, ethylene glycol is preferably used.
These diol components may be used alone or in combination of two or more.

More specifically preferred polyesters are polyethylene terephthalate and polyethylene-
Mention may be made of 2,6-naphthalate and copolymers thereof. Further, these polyesters may be blended with other polymers.

In addition, such polyesters may optionally contain organic lubricants such as flame retardants, heat stabilizers, viscosity reducing agents, antioxidants, ultraviolet absorbers, antistatic agents, pigments, dyes, fatty acid esters, waxes and the like. Alternatively, an antifoaming agent such as polysiloxane can be blended.

Further, in order to impart slipperiness depending on the use, for example, clay, mica, titanium oxide, calcium carbonate, kaolin, talc, wet silica, dry silica, calcium phosphate, aluminum oxide, zirconium oxide, etc. Particles such as inorganic particles, organic particles having acrylic acid, styrene, divinylbenzene or the like as a constituent component, and internal particles using a catalyst during polyester synthesis may be blended.

In order to obtain the effects of the present invention better, the concentration of carboxyl end groups in the polyester is
It is preferably in the range of 15 equivalents / ton or more and 65 equivalents / ton.

In the present invention, when a molten polymer is extruded from a die and then stretched to form a film, the molten polymer extruded from the die is cooled by a cooling drum called a casting drum in order to obtain a surface property of the film. Then, the film is manufactured by a method of preheating to a predetermined temperature while running the film in contact with a roll, stretching and cooling. At this time, at least one of the drum or the roll in contact with the film has a surface roughness of 1S on the outer peripheral surface. It is necessary that the roll has a chrome-plated coating containing not more than 0.5 to 5% of carbon atoms with respect to chromium atoms on the surface as the number of atoms. This makes it possible to produce a film for a long time in a state where the oligomer does not adhere to the surface of the casting drum or roll during the production of the film. The outer peripheral surface here is
By the surface in contact with polymers, sheets and films.

The surface roughness is 1 S or less, preferably 0.6 S or less, more preferably 0.05 to 0.4 S. 1S is JIS-B-060
The Rmax value specified in the surface roughness measurement of No. 1 is 1 μm. The surface roughness can be measured using a commercially available surface roughness meter with a sample length of 1 to 10 mm and a cutoff of 0.1 to 1 mm. In the case where the sample is too large to fit on the surface roughness meter or the like, it is also possible to substitute for this by measuring a sample piece treated in the same manner as the sample.

It is essential that the surface has a chromium plating film containing 0.5 to 5% of carbon atoms with respect to chromium atoms. By satisfying both conditions of the surface roughness and the surface coating composition, it is possible to achieve the purpose that the oligomer does not adhere for the first time. Therefore, for example, one having a chromium plating film containing 0.5 to 5% of carbon atoms with respect to chromium atoms on the surface in a state where the surface roughness exceeds 1 S is not The effect is difficult to exert. Further, in the case of a coating composition other than the present invention, such as hard chrome plating having a surface roughness of 1 S or less, but the surface having no carbon atom, oligomer adhesion may occur to some extent, but the film may not adhere to the film. It leads to surface defects and cannot be used.

The surface film mentioned here is formed by plating an alloy of chromium and carbon (hereinafter abbreviated as Cr-C). Specifically, it is obtained by a method of plating after adding an organic substance such as formic acid and oxalic acid to a chromic acid plating bath, and a method of adding formic acid is preferable (for example, J. El.
ec-trochem. Soc. , 133,681 (1
986). The structure of the obtained plating film is changed by subsequent heat treatment. The crystal structure can be confirmed by X-ray diffraction, but it does not show a clear crystal structure below about 350 ° C.
It is in a so-called amorphous state, and when it exceeds 350 ° C., it shows a crystal structure of chromium and Cr—C. In the present invention, the structural change due to this heat treatment may be amorphous, chrome, or Cr-C, but if there is a scratch on the surface in contact with the film, it is transferred to the film and becomes a surface defect. Therefore, the harder the surface, the better the durability so as not to scratch the surface. Therefore, the surface hardness is preferably 1200 or more in terms of hard Vickers hardness.

The atomic composition of Cr-C plating requires that the number of carbon atoms with respect to chromium atoms is in the range of 0.5 to 5%. When the carbon atom content is less than 0.5%, the oligomer adhesion is not so improved, and there is no great difference from the state of normal hard chromium, which is not good. On the other hand, when the carbon atoms are more than 5%, the plating film layer becomes weak and it is difficult to attain the above-mentioned hard Vickers hardness of 1200 or more.

If the plating film thickness is too thin, it is affected by the softness of the underlying metal, and conversely, if the plating film thickness is too thick, cracks easily occur due to heat or stress strain, resulting in defects. Is preferably 0.1 μm or more and 15 μm or less, more preferably 0.5 μm or more and 10 μm or less.

The underlying metal on which the plating film is placed is not particularly limited, but usually SUS or carbon steel is preferably used.

Further, according to the present invention, the surface of the drum or roll having the above-mentioned surface roughness on which the plating film is placed has a width of 1 to 1 mm.
0 to 10 cracks with a length of 20 μm and a length of 50 μm or more
It is preferable that the number is 0/10 mm ² . The term "crack" as used herein means a crack that can be seen by observing the surface, and can be observed with a microscope having a magnification of 100 to 200 times. If there is only one crack, the length can be measured as it is, but if it becomes terrible, this crack may exist in this visual field like a hexagonal pattern. In such a case, the distance between the intersections is defined as the length of one crack. The presence of cracks is not preferable because when the film comes into contact with the film, the film is scraped at the cracked portion and piles up on the surface of the drum or roll, resulting in transfer to the film surface, scratches, and dents. Furthermore, it contacts with the base metal through the cracks and reacts with them to lead to the precipitation of metal antimony and the precipitation of oligomers, which similarly causes defects on the film surface, which is not preferable.

[0021]

[Characteristics measurement method]

(1) Intrinsic viscosity [η] After drying the sample at 120 ° C. for 3 hours, 0.1 g ± 0.0
005 g was weighed and dissolved in o-chlorophenol by stirring at 160 ° C. for 15 minutes. After cooling, the viscosity at 20 ° C. was measured with a Yamatrabotic AVM-10S type automatic viscosity meter.

(2) Carboxyl terminal concentration [Method of Maurice et al. [Anal. Chim. Act
a. , 22, 363 (1960)].

(3) Evaluation of cracks on the roll surface The roll surface was observed with a dark field microscope at 100 to 200 times at an arbitrary position within a range of 10 mm ² , and cracks having a width of 1 to 20 μm and a length of 50 μm or more were observed. ,It was measured.

(4) Roll Surface Hardness The hard Vickers hardness was measured according to the usual method and used as the surface hardness.

(5) Evaluation of Adhesion of Oligomer When actually manufacturing a film, it was visually judged whether or not white powder adhered to the roll surface. When white powder was accumulated and defects such as scratches and digs were generated on the film surface, the film formation was stopped, and it was judged that the longer the time, the better the film formation stability.

(6) Surface roughness In accordance with JIS-B-0601, using a contact type surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd., measurement length 4 mm, cutoff 0.25 m
Rmax was measured in m.

[0027]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Example 1 Polyethylene terephthalate (Intrinsic viscosity [η] = 0.6
No. 21, pellets having a carboxyl terminal group concentration of 40.3 equivalents / ton and a melting point of 256 ° C.) were melted at 275 ° C., extruded from a T die, and rapidly cooled with a casting drum cooled to 25 ° C. to obtain an amorphous sheet. After that, 4 metal rolls (N
O. 1 to NO. 4) is heated to 90 ° C. and stretched 3.5 times in the longitudinal direction between a silicon roll (NO. 5) and a ceramic roll (NO. 6), and then 6 metal rolls (NO. 7 to 12). ), And the uniaxially stretched film was obtained. Then, both sides of the obtained uniaxially stretched film were held by clips, heated with hot air, stretched 3.8 times in the width direction at 95 ° C., and heat-set at 120 ° C. for 2 seconds to give a thickness of 15.6 μm.
A biaxially stretched polyethylene terephthalate film was obtained.

The NO. 1 to NO. 4 rolls are hard chrome plated, NO. 7-NO. Roll 12 having a surface roughness of 0.3 S and a chromium plating film containing 1.5% of carbon atoms with respect to chromium atoms (surface hard Vickers hardness = 1500) was used. In addition, this roll surface 15
When observed under a microscope at a magnification of 0, no crack was observed.

It is very stable during the production of the film,
O. 7-NO. It was possible to form a film for 80 hours without deposits that appeared to be oligomers in No. 12. After film formation, N
O. 7-NO. When the surface of No. 12 was observed, neither adhesion of oligomers nor cracks were observed.

Example 2 Polyethylene terephthalate (Intrinsic viscosity [η] = 0.6
No. 18, pellets having a carboxyl terminal group concentration of 42.7 equivalents / ton and a melting point of 256 ° C.) were melted at 275 ° C., extruded from a T die and rapidly cooled by a casting drum cooled to 25 ° C. to obtain an amorphous sheet. After that, 4 metal rolls (N
O. 1 to NO. 4) is heated to 90 ° C. and stretched 3.3 times in the longitudinal direction between a silicon roll (NO. 5) and a ceramic roll (NO. 6), and then 6 metal rolls (NO. 7 to 12). ), And the uniaxially stretched film was obtained. Then, both sides of the obtained uniaxially stretched film were held by clips, heated with hot air, stretched 3.8 times in the width direction at 95 ° C, and heat-set at 120 ° C for 2 seconds, and then four metal rolls (NO. 13 to NO. 16) and heated to 140 ° C., and further 5 metal rolls (NO. 17 to NO. 21)
Again by 1.2 times in the longitudinal direction using
Was heat-treated for 2 seconds to obtain a biaxially stretched polyethylene terephthalate film having a thickness of 8.7 μm.

The NO. 1 to NO. 4 rolls are hard chrome plated, NO. 7-NO. 12 and NO. 17-N
O. For No. 21, a roll (surface hard Vickers hardness = 1600) having a surface roughness of 0.3 S and a chromium plating film containing 2.0% of carbon atoms with respect to chromium atoms was used. Further, the surface of this roll was observed under a microscope at a magnification of 150 times, but no crack was observed.

It is very stable during the production of the film,
O. 7-NO. 12 and NO. 17-NO. It was possible to form a film for 75 hours without deposits that appeared to be oligomers in No. 21. After completion of film formation, NO. 7-NO. 12 and NO. 17-NO. When the surface of No. 21 was observed, neither adhesion of oligomers nor cracks were observed.

Comparative Example 1 As a roll of the prior art, NO. 7-NO. Example 1 except that hard chrome plating with a surface roughness of 1.1S was used for 12
A biaxially stretched polyethylene terephthalate film was obtained in the same manner as above, but oligomers adhered to the roll like white powder in 24 hours and many feather-like scratches were generated on the film surface, so film formation was stopped and the roll was washed. did.

Comparative Example 2 NO. 7-NO. A biaxially stretched polyethylene terephthalate film was obtained in the same manner as in Example 1 except that the surface roughness of No. 12 was 1.1 S. However, the oligomer adhered like a white powder on the roll in 53 hours, and the film surface had feathers. Since many scratches were generated, the film formation was stopped and the roll was washed.

Comparative Example 3 As a roll of the prior art, NO. 17-NO. A biaxially stretched polyethylene terephthalate film was obtained in the same manner as in Example 1 except that hard chrome plating having a surface roughness of 1.1S was used for No. 21, but the oligomer adhered to the roll like white powder in 19 hours, 22 digging scratches on the surface
Since the film broke in a certain time, film formation was stopped and the roll was washed.

[0037]

Since the present invention has the above-mentioned structure, it has the following effects. That is, since it is possible to produce a film for a long time in a state where the oligomer (low polymer) present in the polymer does not adhere to the surface of the casting drum or roll during the production of the film, surface defects such as scratches and dents It is possible to stably produce an excellent film that does not have any. Therefore, it is excellent as a manufacturing method and a manufacturing apparatus of a film for base recording such as magnetic recording, particularly 8 mm, DVC (digital video cassette) and optical.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29K 77:00 B29L 7:00

Claims (6)

[Claims] 1. The outer peripheral surface has a surface roughness of 1 S or less, and the surface has a number of carbon atoms relative to chromium atoms of 0.5.
A film manufacturing apparatus comprising a film manufacturing drum or roll having a chrome-plated coating containing 5% to 5%. 2. The width 1 existing on the surface of the chrome-plated coating part.
~ 20 μm and 100 cracks with a length of 50 μm or more
The number of pieces / 10 mm ² or less, The film manufacturing apparatus according to claim 1, wherein 3. A film manufacturing drum or roll comprising:
Casting drum for film production, preheating roll,
A stretching roll, a cooling roll, a tension adjusting roll, a guide roll or a nip roll.
Alternatively, the film manufacturing apparatus according to claim 2. 4. When a molten polymer is extruded from a die and then stretched to form a film, at least one drum or roll in contact with the film has a surface roughness of 1 S or less and a carbon atom with respect to chromium atoms on the surface. A method for producing a film, which comprises using a film-producing drum or roll having a chrome-plated coating containing 0.5 to 5% of atoms as the number of atoms. 5. The method for producing a film according to claim 4, wherein the molten polymer is at least one selected from polyesters, polyamides, polyolefins, their copolymers and alloys. 6. The production of a film according to claim 5, wherein the polyester is at least one selected from polyethylene terephthalate, polyethylene-2,6-naphthalate and copolymers and composites thereof. Method.