JP2002331564A - Method for manufacturing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an excellent film having no line-like defect on its surface by means of a molten extrusion method. SOLUTION: A film is manufactured by melting and extruding a thermoplastic resin by use of an extruder and a die wherein surface roughness Ry of a connecting pipe portion from the outlet of the extruder to the die is not more than 1.0S, surface roughness Ry of a die lip portion is not more than 0.5S, surface roughness Ry of the flow portion of the die is not more than 0.6S, surface roughness Ry of a die manifold portion is not more than 0.7S and surface roughness Ry of a die supply portion is not more than 0.8S respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a film, and more particularly, to a deposit caused by an additive in a polymer or a degradation product of a polymer, and a streak defect on a film surface caused by the deposit. The present invention relates to a method for producing an excellent film free from occurrence of cracks.

[0002]

2. Description of the Related Art Conventionally, in forming a film using a thermoplastic polymer, a method has been adopted in which the thermoplastic polymer is melted and extruded from a die (die) to form a film. However, according to the conventional method, the catalyst and additives present in the polymer and the deteriorated product of the polymer are deposited on the inner surface of the die during film production, causing a streak-like defect due to the attached material. In optical applications, resulting in an optical disadvantage. Conventionally, in order to avoid this, studies have been made on a plating method or the like for a portion in contact with a polymer (for example, Japanese Patent Application Laid-Open Nos. 1-280525 and 4-4-2).
JP-A-212827, JP-A-4-214319,
JP-A-9-225989) is 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, catalysts and additives present in a molten polymer and a polymer degraded product are removed from a film. It is an object of the present invention to provide a method for producing a film that enables production of a film in a state where the film does not precipitate and adhere to the surface of a die or the like during production.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the wall of the channel connecting the outlet of the extruder and the die, which contacts the molten polymer during the film production, is formed. The inventors have found that, if the surface roughness is set to a predetermined value, such a problem can be solved and a film having no surface defects as described above can be manufactured, and the present invention has been achieved.

That is, the gist of the present invention is to provide a method for producing a film in which a thermoplastic resin is melt-extruded using an extruder and a die. _{The present invention} is directed to a film manufacturing method in which _y is 1.0S or less and the surface roughness _Ry of the die lip portion is 0.5S or less.

In the method of manufacturing a film according to the present invention, the surface roughness _Ry of the die flow path is 0.6 S or less, the surface roughness _Ry of the die manifold is 0.7 S or less, and the surface roughness _Ry of the die supply path is The degrees _Ry can each be less than 0.8S.

The thermoplastic resin contains a thermoplastic resin (A) having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in a side chain. It can be a thermoplastic resin (B).

The thermoplastic resin (A) has the formula (1)

[0009]

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(In the formula (1), R ¹ , R ² and R
³ each independently represents hydrogen or an alkyl group having 1 to 8 carbon atoms. ) And the formula (2)

[0011]

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(In the formula (2), R represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms.)
Here, the content of the repeating unit of the formula (1) is 30 to 80 mol% based on the total repeating units of the thermoplastic resin (A), and the content of the repeating unit of the formula (2) is 70 to 20 based on the total repeating units of (A)
Mol%, and the thermoplastic resin (B) is represented by the formula (3)

[0013]

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(In the formula (3), R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms.)

[0015]

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(In the formula (4), R ⁶ and R ⁷ are
Each independently represents hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ represents hydrogen, an alkyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an alkoxy group, or a nitro group. And the content of the repeating unit of the formula (3) is 20 to 50% by weight based on the total repeating units in the thermoplastic resin (B), and the formula (4) Is from 50 to 80% by weight, and the content of the thermoplastic resin (A) is based on the sum of the amount of the thermoplastic resin (A) and the amount of the thermoplastic resin (B). Is 50 to 80% by weight, and the content of the thermoplastic resin (B) may be 20 to 50% by weight.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies to solve the above problems, the present inventors have found that a specific portion after the extruder outlet which comes into contact with a molten polymer during film production has a predetermined surface roughness. As a result, the present inventors have found that a film free of the above-mentioned streak-like surface defects can be produced, and have reached the present invention.

That is, in a film production method in which a thermoplastic resin is melt-extruded using an extruder and a die, conventionally, in order to produce a film having no surface defects, the surface roughness of a die lip is made as small as possible. However, it is not sufficient by itself, the surface roughness _Ry of the die lip portion is set to 0.5S or less, and the molten polymer at the connection pipe portion at the outlet of the extruder far upstream of the die lip portion. It has been found that a film having few surface defects can be manufactured by using an apparatus having a surface roughness _Ry of 1.0 S or less at a portion where the surface contacts.

In the present invention, the surface of the die lip portion having a surface roughness _Ry of 0.5 S
Hereinafter, the die channel surface roughness _Ry is 0.6S or less, the die manifold surface roughness _Ry is 0.7S or less, the surface roughness _Ry of the die supply passage is 0.8S or less, and the extruder outlet. It has been found that by using an apparatus in which the surface roughness _Ry of the connecting pipe section from the to the die supply path section is 1.0 S or less, a film having no further surface defects can be produced.

The portion where the molten polymer contacts in the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing an example of the configuration of a film extrusion molding apparatus used in the present invention. In FIG. 1, an extruder 2 for extruding a film comprises an extruder 4, a die 6, and a connection pipe 10 for connecting an exit of the extruder 4 and a die supply path 8 of the die 6. The die 6 includes a die supply path section 8, a die manifold section 14, a die flow path section 12, and a die lip section 15. The molten polymer extruded from the extruder 4 passes through the connecting pipe section 16 of the connecting pipe 10 and reaches the supply path section 8 which is a flow path from the flow of the molten polymer of the die 6 to the die manifold section 14. Then, the ink is discharged through the die manifold section 14 to the die lip section 15 via the die flow path section 12. The die manifold section 14 is located between the die supply path section 8 and the die flow path section 12, and has a larger cross-sectional area of the molten polymer flow path than the die supply path section 8 and the die flow path section 12. Are provided for even distribution of the molten polymer.

The term "molten polymer" in the present invention means a thermoplastic resin which is plastically flowed by heating to a molten state by heating it to a temperature higher than its flow starting temperature, and is a typical example of such a thermoplastic resin. , Ester resins,
Examples include amide resins, olefin resins, cyclic olefin resins, acrylic resins, maleimide resins, glutarimide resins, vinyl resins, and copolymers thereof. Further, two or more of these thermoplastic resins may be blended. The method for producing a film of the present invention has a remarkable effect particularly on a resin having a strong adhesion to a metal in a molten state.

Above all, a resin containing a resin in which an olefin-maleimide resin (thermoplastic resin A) and a styrene-acrylonitrile resin (thermoplastic resin B) are combined, and having a strong adhesion to a metal in a molten state. Has a remarkable effect on

More specifically, the thermoplastic resin (A)
Is the equation (1)

[0024]

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(In the formula (1), R ¹ , R ² and R ³
Each independently represents hydrogen or an alkyl group having 1 to 8 carbon atoms. The number of carbon atoms in the alkyl group is preferably from 1 to 4, more preferably from 1 to 2. ) And the formula (2)

[0026]

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(In the formula (2), R represents hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. The alkyl group preferably has 1 carbon atom.
To 4, more preferably 1 to 2. Wherein the content of the repeating unit of the formula (1) is 30 to 80 mol% based on the total repeating units of the thermoplastic resin (A), and the formula (2) Is 70 to 20 mol% based on the total repeating units of the thermoplastic resin (A), and the thermoplastic resin (B) is represented by the formula (3):

[0028]

Embedded image

(In the formula (3), R ⁴ and R ⁵ are
Each independently represents hydrogen or an alkyl group having 1 to 8 carbon atoms. The number of carbon atoms in the alkyl group is preferably from 1 to 4, more preferably from 1 to 2. )) And the formula (4)

[0030]

Embedded image

(In the formula (4), R ⁶ and R ⁷ are
Each independently represents hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ represents hydrogen, an alkyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an alkoxy group, or a nitro group. The carbon number of the alkyl group is preferably 1 to 4,
More preferably, it is 1-2. The carbon number of the alkoxy group is preferably 1 to 20, more preferably 1
-8, and more preferably 1-4. And the content of the repeating unit of the formula (3) is 20 to 50% by weight based on the total repeating units in the thermoplastic resin (B), and the formula (4) Is from 50 to 80% by weight, and the content of the thermoplastic resin (A) is based on the sum of the amount of the thermoplastic resin (A) and the amount of the thermoplastic resin (B). Is 50-80
% By weight and the content of the thermoplastic resin (B) is 2%.
It is particularly effective for the production of films consisting of combined resins, which are 0 to 50% by weight.

The film obtained by using such a resin is useful as an optical film having an extremely small retardation in the inner surface and the thickness direction and having excellent transparency. In particular, this film is suitable as a polarizer protective film for a polarizing plate used in a liquid crystal display device or the like.

If necessary, a flame retardant, a heat stabilizer, a lubricant, an ultraviolet absorber, an antistatic agent, an antioxidant, a plasticizer, a pigment, a dye, etc. may be added to the thermoplastic resin. I can do it.

Further, in order to impart lubricity according to the intended use, for example, inorganic particles such as clay, mica, titanium oxide, calcium carbonate, wet silica and dry silica, acrylic acids, styrene, urethane and the like are used. Organic particles as components can also be blended.

The surface roughness _Ry of the die lip in contact with the molten polymer is preferably 0.5 S or less, more preferably 0.4 S or less.
Hereinafter, the range of 0.05 to 0.2 S is more preferable. If 0.5S is exceeded, die line generation is observed,
If the content is 0.05 S or less, the cost for polishing becomes large, which is not economically preferable. Surface roughness R here
_y is an _Ry value defined in the surface roughness measurement of JIS-B-0601.

The surface roughness _Ry of the die flow path is preferably 0.6S or less, more preferably 0.4S or less, and further preferably 0.0S or less.
A range of 5 to 0.3S is preferred. When 0.6S is exceeded, generation of a die line is recognized.
The cost for polishing is large, which is economically undesirable.

The surface roughness _Ry of the die manifold section is set to 0.1.
7S or less is preferable, 0.5S or less is more preferable, and the range of 0.05 to 0.4S is more preferable. If 0.7 S is exceeded, generation of a die line is recognized, and if it is 0.05 S or less, the cost for polishing becomes large, which is not economically preferable.

The surface roughness _Ry of the die supply path is preferably 0.8S or less, more preferably 0.5S or less, and more preferably 0.5S or less.
A range of 1 to 0.4 S is preferred. When 0.8S is exceeded, generation of a die line is recognized.
The cost for polishing is large, which is economically undesirable.

The surface roughness _Ry of the connecting pipe from the extruder outlet to the die supply path is preferably 1.0S or less, more preferably 0.8S or less, and further preferably in the range of 0.2 to 0.5S. preferable. If it exceeds 1.0S, generation of a die line is recognized, and if it is 0.2S or less, the cost for polishing becomes large, which is not economically preferable. Further, the material of the device used in the present invention may be any material such as stainless steel, ultra-hard steel, hard chrome plating, ceramic coat, Teflon (registered trademark) coat, and any material that can secure the surface roughness. .

The surface roughness in the present invention is determined according to JIS-B-
It is an _Ry value measured in accordance with 0601. The _Ry value was measured using a contact-type surface roughness meter manufactured by Tokyo Seimitsu with a measurement length of 4 mm and a cutoff of 0.25 mm. Further, for a portion that cannot be directly measured, such as a connection pipe, a test piece subjected to the same polishing was prepared and measured.

[Examples] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to only these examples.

Example 1 65 parts by weight of a pelletized copolymer composed of isobutene and N-methylmaleimide (N-methylmaleimide content: 50 mol%, glass transition temperature: 157 ° C.), and acrylonitrile content: 27% by weight To 35 parts by weight of the acrylonitrile / styrene copolymer pellets, 0.2 parts by weight of Adeka Mark AO-60 as a stabilizer was added and blended to prepare a test raw material. Using this raw material, a 40 mm extruder (L / D = 24) was fitted with a hard chromium-plated connection tube and a T-die to form a melt extruded film. At this time, the surface roughness of the connection portion was 0.5 S, the surface roughness of the die supply path portion was 0.4 S, the surface roughness of the die manifold portion was 0.4 S, and the surface roughness of the die flow channel portion was 0 S. 0.3S, and the surface roughness of the die lip portion was 0.2S. No streak-like defects were observed on the surface of the obtained film.

Example 2 A melt extruded film was produced in the same manner as in Example 1 except that the material of the die lip was coated with ceramic (WC). No streak-like defects were observed on the surface of the obtained film.

(Comparative Example 1) A melt-extruded film was formed under the same conditions as in Example 1 except that the surface roughness of the connecting tube was changed to 1.2S. On the surface of the obtained film, a streak-like defect which was a practical problem as an optical film or a magnetic recording film was observed.

Comparative Example 2 A melt extruded film was formed under the same conditions as in Example 1 except that the surface roughness of the die lip was changed to 0.7 S. On the surface of the obtained film, a streak-like defect which was a practical problem as an optical film or a magnetic recording film was recognized.

Example 3 A melt extruded film was formed under the same conditions as in Example 1 except that the surface roughness of the die flow path was changed to 0.8 S. Although a slight streak-like defect was observed on the surface of the obtained film, it was of no practical problem.

Example 4 A melt extruded film was formed in the same manner as in Example 1 except that the surface roughness of the die manifold portion was changed to 0.8 S. Although a slight streak-like defect was observed on the surface of the obtained film, it was of no practical problem.

Example 5 A melt extruded film was formed under the same conditions as in Example 1 except that the surface roughness of the die supply path was changed to 1.0 S. Although a slight streak-like defect was observed on the surface of the obtained film, it was of no practical problem.

[0049]

According to the present invention having the above-described structure, the following effects can be obtained. In other words, the film can be produced in such a state that the catalyst and additives present in the polymer and the deteriorated product of the polymer do not precipitate and adhere to the flow wall of the flow path of the molten polymer such as a die during the film production. In addition, an excellent film having no streak-like surface defects can be stably manufactured. Therefore, the film production method of the present invention is excellent as a film production method for a wide variety of applications including magnetic recording applications and optical applications.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a configuration of a film extrusion molding apparatus used in the present invention.

[Explanation of symbols]

 2: Extruder 4: Extruder 6: Die 8: Die supply path 10: Connection pipe 12: Die flow path 14: Die manifold 15: Die lip 16: Connection pipe

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 23/02 C08L 23/02 25/00 25/00 33/18 33/18 35/00 35/00 101/02 101 / 02 // B29C 47/36 B29C 47/36 B29K 101: 12 B29K 101: 12 B29L 7:00 B29L 7:00 F term (reference) 4F207 AA13 AC01 AG01 AJ02 AJ09 AM32 KA01 KA17 KL52 KL55 KL62 KL84 KL91 4J002 BB101 BB101BB BB171 BB191 BC062 BC082 BC092 BC112 BC122 BG092 BG102 BH021 FD170 GP00 GS01 4J100 AA01P AA15P AB01P AB07P AM01Q AM43Q AM45Q AM47Q BA03P BA04P BA41P BB01P BB03P BB05P BB0724 JA02 CA04

Claims (4)

[Claims] 1. A method for producing a film in which a thermoplastic resin is melt-extruded using an extruder and a die, wherein a surface roughness _Ry of a connecting pipe portion from an extruder outlet to a die is 1.0S or less, and a die lip portion is provided. The method for producing a film, wherein the surface roughness _Ry of each is 0.5S or less. 2. A 0.6S the surface roughness _{R y} of the die flow path portion below 0.7 S of the surface roughness _{R y} of the die manifold or less, the surface roughness _{R y} of the die feed passage 0.8S The method for producing a film according to claim 1, wherein: 3. The thermoplastic resin (A) having a substituted or unsubstituted imide group in a side chain, and a substituted or unsubstituted phenyl group in a side chain,
The film production method according to claim 1, wherein the resin composition is a resin composition containing a thermoplastic resin (B) having a nitrile group. 4. The thermoplastic resin (A) has a formula (1) (In the formula (1), R ¹ , R ² and R ³ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms.) And a repeating unit represented by the formula (2): (In the formula (2), R represents a hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms.) ) Is the content of the thermoplastic resin (A)
And the content of the repeating unit of the formula (2) is 70 to 20 mol% based on the total repeating units of the thermoplastic resin (A).
Wherein the thermoplastic resin (B) is represented by the formula (3): (In the formula (3), R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms.) And a repeating unit represented by the formula (4): (In the formula (4), R ⁶ and R ⁷ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms;
⁸ is hydrogen, an alkyl group having 1 to 8 carbon atoms, a halogen group,
It represents a hydroxyl group, an alkoxy group, or a nitro group. And the content of the repeating unit of the formula (3) is 20 to 50% by weight based on the total repeating units in the thermoplastic resin (B), and the formula (4) Is 50 to 80% by weight, and the content of the thermoplastic resin (A) is based on the sum of the amount of the thermoplastic resin (A) and the amount of the thermoplastic resin (B). Is 50 to 80% by weight, and the content of the thermoplastic resin (B) is 20 to 50% by weight.