JP3409562B2 - Film manufacturing die and film manufacturing method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a film, and more particularly, to a catalyst or an additive in a polymer and a deposit caused by a deteriorated product of the polymer and a film surface generated thereby. The present invention relates to a method and an apparatus for manufacturing an excellent film that does not cause streak defects.

[0002]

2. Description of the Related Art Conventionally, when forming a film using a thermoplastic polymer, a method has been used in which the thermoplastic polymer is melted and extruded from a die, and then stretched as necessary to form the film. Was there. However, in the conventional method, catalysts and additives existing in the polymer and polymer degradation products are deposited on the surface of the die during film production, and streak-like defects are generated by the deposits, and in the magnetic recording application, recording This was a problem because it dropped out and caused optical defects in optical applications. Conventionally, in order to avoid this, a study has been added by a plating method or the like of a portion in contact with a polymer (for example, JP-A-5-24097).
Japanese Patent Laid-Open No. 4-212827 and Japanese Patent Laid-Open No. 4-2.
14319, JP-A-4-193518)
But it was still insufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. Specifically, the catalysts and additives present in the polymer and the deteriorated products of the polymer produce a film. 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 in a state where the film is not deposited and adhered on the surface of the die.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that if at least a part of a die that comes into contact with a molten polymer during the production of a film is made of a specific material, The inventors have reached the present invention by solving such problems and finding that a film having no surface defects as described above can be produced.

That is, the die for producing a film of the present invention is a chromium containing at least a part of the surface containing silicon atoms to chromium atoms such that the ratio of silicon atoms / chromium atoms is 10 ⁻⁴ or more as the SIMS intensity ratio. It has a plating film, or contains carbon atoms in at least a part of the surface such that carbon atoms with respect to oxygen atoms have a strength of SIMS such that carbon atoms> oxygen atoms , and has a surface roughness.
In the method for producing a film of the present invention, a molten polymer is extruded from a die and then stretched to form a film. At least a part of the surface of the die to be contacted with silicon atom to silicon atom to SI atom
The intensity ratio of MS is 10 ^-4 silicon atoms / chromium atoms
A method for producing a film, which comprises using a die having a chrome-plated coating contained as described above, or extruding a molten polymer from the die, and then stretching the film to form a molten polymer. At least a part of the surface of the die to be contacted with has a chromium plating film containing carbon atoms with respect to oxygen atoms so that the SIMS strength is such that carbon atoms> oxygen atoms , and the surface roughness is 1S or less. The method for producing a film is characterized by using the film forming die.

[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. Representative 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, polyolefins and their copolymers are preferable, and polyesters and their copolymers are more preferable.

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 or more.

In the present invention, the above-mentioned thermoplastic polymer is melted, the melted polymer is extruded from the die, and then stretched as necessary to form a film, which is a molten polymer. mouthpiece silicon atom / chromium atom a silicon atom as the intensity ratio of SIMS is a chromium plating film containing so as to be 10 ^-4 or more with respect to the chromium atom in at least a portion of the surface of the die in contact with, or at least A part of the surface contains carbon atoms with respect to oxygen atoms so that the SIMS intensity is such that carbon atoms> oxygen atoms , and the surface roughness is 1S.
It is necessary for the die for film production to have the following chrome-plated coating. The preferable range of silicon atom / chromium atom is 5 × 10 ⁻⁴ or more and 10 ⁻¹ or less in terms of SIMS intensity ratio of silicon atom to chromium atom. As a result, it is possible to produce a film for a long time in a state where the catalyst and additives in the polymer and the deteriorated product of the polymer do not adhere to the surface of the die which comes into contact with the molten polymer during the production of the film. The intensity ratio of SIMS referred to here is, as described in the section of characteristic evaluation, SIMS (Secondary I
On Mass Spectrometry) means an average secondary ion intensity ratio between a depth of 100 nm and 2000 nm from the surface layer.

The surface roughness of the chromium plating film portion is preferably 1 S or less, more preferably 0.6 S or less, and further preferably in the range of 0.05 to 0.4 S. 1S means that the Rmax value specified in JIS-B-0601 surface roughness measurement 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. Further, in the case where the sample is too large to fit on the surface roughness meter, it is possible to substitute this by measuring a sample piece that has been subjected to the same treatment as the sample.

Further, it is preferable that the chromium plating film has a chromium plating film containing 0.5 to 5% of carbon atoms with respect to chromium atoms as the number of atoms.

The surface film of the present invention can be obtained, for example, by a method of adding a silicon compound such as hexafluorosilicic acid to a chromic acid plating bath. In addition, formic acid,
It is preferable to add an organic substance such as oxalic acid, because the above-mentioned carbon is contained. The structure of the obtained plating film is changed by subsequent heat treatment. The crystal structure is X
Although it can be confirmed by line diffraction, it is in a so-called amorphous state in which a clear crystal structure is not shown at about 380 ° C. or lower, and a crystal structure comes to be displayed at higher than about 380 ° C. In the present invention, structural change due to this heat treatment, but may be a crystal structure be amorphous, in order not enter scratches for use on the plating surface, better surface is hard is good durability, therefore, The surface hardness is preferably a hard Vickers hardness of 1000 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, in the present invention, it is preferable that the surface of the die on which the plating film is placed has a width of 1 to 20 μm and a length of 50 μm or more in the range of 0 to 100 cracks / 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 one crack, the length can be measured as it is, but if it becomes terrible,
Some cracks exist in this view 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 molten polymer comes into contact, the molten polymer comes into contact with the underlying metal through the cracks and reacts to lead to the deposition of metal antimony and the deposition of oligomers, resulting in streaky film surface defects.

[0020]

[Characteristics measurement method]

(1) SIMS ion intensity ratio Secondary ion mass spectrometer A-DI manufactured by German ATOMIKA
Using DA3000, the primary ion O ₂ was 40 × 40 at an ion energy of 12 kev and a primary ion current of 500 nA.
Metal analysis is performed from the surface layer to a depth of 2500 nm in the μm region to obtain secondary ion intensities Cr ⁺ and Si ⁺ (cps),
The average (100 nm to 2000 nm) was taken from the surface layer, and the ratio (Si ⁺ / Cr ⁺ ) was determined.

Further, using the same apparatus, the primary ions Cs ⁺
The ion energy is 12 kev and the primary ion current is 100
2500 nm from the surface layer in the 200 x 200 μm region with nA
Of the secondary ion intensity O ⁻ , C ⁻ (c
ps) was obtained, and the respective intensities from 100 nm to 5000 nm were compared from the surface layer.

(2) 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.

(3) Carboxyl terminal concentration method by Maurice et al. [Anal. Chim. Act
a. , 22, 363 (1960)].

(4) Evaluation of cracks on the surface of the die The surface of the die is observed with a dark field microscope of 100 to 200 times at an arbitrary position within a range of 10 mm ² , and the width is 1 to 20 μm and the length is 5.
A crack (crack) of 0 μm or more was observed and measured.

(5) Surface hardness of spinneret The hard Vickers hardness was measured according to a conventional method and used as the surface hardness.

(6) Evaluation of Base Streak The polymer was melted and extruded from the base, and the generation of streaks was visually observed under polarized light. Those that do not generate streaks for a long time are good, and those that generate streaks in a short time are bad.

(7) Surface roughness According to JIS-B-0601, using a contact type surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd., measuring length 4 mm, cutoff 0.25 m
Rmax was measured in m.

[0028]

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

Example 1 A straight land portion and a lower surface of a die for film production using DH2F as a base material were polished to 0.06S, and a corner R was finished to 5 μm. A plating film having a thickness of 7 μm was formed on this portion in a bath of chromic acid, formic acid and hexafluorosilicic acid, and baked at 300 ° C. The surface roughness after plating was 0.1 S and the corners were 6 μm. Further, when the metal analysis of the plated coating was carried out by SIMS, it was found that Si ⁺
/ Cr ⁺ = 10 ⁻³ , C ⁻ > O ⁻ , no cracks were observed on the surface, and the surface hardness was Hv1200. This was set to have a width of 400 mm and a slit interval of 2 mm.

Next, polyethylene terephthalate (intrinsic viscosity [η] = 0.618, carboxyl end group concentration 3)
9.5 equivalents / ton, melting point 256 ° C) pellets 285
It was melted at 0 ° C., extruded through this die, cooled on a casting drum at 30 ° C., and a 200 μm thick sheet was wound at 40 m / min. Even after 96 hours from the start of extrusion, no streak-like defects were generated and no polymer deterioration product was attached to the lower part of the die, which was very good.

Example 2 Polyethylene-2,6-naphthalate (intrinsic viscosity [η]
= 0.650, carboxyl end group concentration 25.4 equivalents /
Ton, melting point 275 ° C.) at 305 ° C.,
Extruded through the die used in Example 1, similarly at 30 ° C.
A 200 μm thick sheet was wound at 40 m / min. Even after 96 hours from the start of extrusion, no streak-like defects were generated and no polymer deterioration product was attached to the lower part of the die, which was very good.

Comparative Example 1 A film was produced by the same method as in Example 1 without plating with the die for producing a film used in Example 1. A streak-like defect was generated on the surface of the film 12 hours after the film formation, and a polymer deterioration product was adhered to the lower part of the die.

When the die was disassembled, the polymer was depolymerized with triethylene glycol, and the metal surface was observed. It was found that metal antimony was attached to the straight land portion.

Comparative Example 2 Hard chrome plating having a thickness of 80 μm was applied to only the straight land portion of the die used in Comparative Example 1 by a usual method, and the surface was polished. Surface roughness after polishing is 0.6S, corner is 4
It was 0 μm. In addition, the metal analysis in the plating film is performed by S
When carried out by IMS, Si ⁺ / Cr ⁺ = 10 ⁻⁵ ,
C ⁻ <O ⁻ , and the surface hardness was Hv850. This was set to have a width of 400 mm and a slit interval of 2 mm.

When a film was produced in this state in the same manner as in Example 1, a streak-like defect was generated on the film surface 25 hours after the film was formed, and a polymer deterioration product was also attached to the lower part of the die.

When the die was disassembled, the polymer was depolymerized with triethylene glycol, and the metal surface was observed. It was found that the metal antimony was attached to the straight land portion.

[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 in which the catalysts and additives present in the polymer and the deteriorated products of the polymer do not adhere to the surface of the die during the production of the film, it is excellent in that there are no streaky surface defects. The film can be stably manufactured. 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.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI // B29L 7:00 B29L 7:00 (56) Reference JP-A-5-24097 (JP, A) JP-A-4-299115 (JP, A) JP-A-4-214319 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96 B29C 33/38 C25D 5/26 C25D 7 / 00

Claims (7)

(57) [Claims] 1. A silicon atom / chromium atom is present as a SIMS intensity ratio on at least a part of the surface in a silicon atom / silicon atom ratio.
Film production die, wherein the chromium atom is a chromium plating film containing as a 10 ^-4 or more. 2. At least a part of the surface contains carbon atoms with respect to oxygen atoms such that the SIMS intensity is such that carbon atoms> oxygen atoms , and the surface roughness is 1S or less. A die for film production, which has a plating film. 3. The surface roughness of the chromium plating film portion is 1S.
The film manufacturing die according to claim 1, wherein: 4. A chromium plating epithelial membrane unit width present on the surface 1~20μm and length 50μm or more cracks, the die is characterized in that from 0 to 100 pieces / 10 mm ² claims 1 A die for producing a film according to any one of Item 3. 5. When a molten polymer is extruded through a die to form a film, at least a part of the surface of the die which is in contact with the molten polymer has a silicon atom to a chromium atom in a SIMS intensity ratio of silicon atom / chromium atom of 10.
Method of producing a film which comprises using a die comprising a chromium plating film containing such a ^-4 or more. 6. When a molten polymer is extruded through a spinneret to form a film, carbon atoms with respect to oxygen atoms are added to at least a part of the surface of the spinneret in contact with the molten polymer.
Contains so that carbon atom> oxygen atom as strength of MS
And a film manufacturing die comprising a chrome-plated coating having a surface roughness of 1 S or less . 7. The method for producing a film according to claim 5, wherein the molten polymer is at least one selected from polyesters, polyamides, polyolefins, their copolymers and alloys. .