JP2003251678A - Film manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method in melt extrusion molding of a thermoplastic resin transparent film, which does not reduce haze of the film and does not cause mutual adhesion (blocking) between films in an obtained product roll. Is to do. SOLUTION: In a method of mixing a filler into a thermoplastic resin composition, melt-extruding and molding into a film, a method for producing a film is characterized in that the filler is fused with an additive and then mixed with the thermoplastic resin. The above problem is solved. Preferred additives are stabilizers or ultraviolet absorbers, and the average particle size of the filler is preferably 0.1 to 1.0.
001 to 10 μm, and a preferable content of the filler is 0.04 to 0.3% by weight based on the weight of the thermoplastic resin composition (including the filler). A preferred method of fusing is a method of mixing the filler and the additive under high shear.

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 produce a film which does not cause mutual sticking (blocking) between the films in the obtained product roll without reducing the haze of the film. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, when forming a film using a thermoplastic polymer, in order to prevent blocking between films in a product roll, a method of inserting interleaving paper at the time of winding, forcing the end of the film A method of scratching the film to form a minute gap between the films (knurling) is adopted, but since the former uses a film other than the product, the manufacturing cost increases and the interleaf paper after use becomes a waste material, Environmentally unfavorable. The latter has the problem that the end part is not used as a product but becomes a waste material by scratching the end part, and the film in the center part is blocked during transportation and storage because of minute voids only at the end part. Was there.

In order to solve such a problem, there is a technique in which a filler is added at the time of film formation to form fine irregularities on the film surface to prevent blocking, and JP-A-11-001562 discloses. JP 2
No. 001-300165 is known, but these techniques are a method of adding a filler at the time of producing a thermoplastic resin which is a main raw material, or a resin when a film is formed by a solution casting method. This is a method of dispersing a filler in a solution. However, when the filler is added to the resin raw material containing no filler, or when the melt extrusion is performed by further adding the filler to the resin raw material,
There is a problem in the dispersibility of the resin and the filler, or the handling property. For example, a master batch method in which a high-concentration filler is preliminarily dispersed and mixed in a part of the main raw material resin, and this is diluted with the main raw material during extrusion, has a high viscosity of the main raw material resin,
Excessive energy is required for good dispersion, and in many cases, there is an adverse effect such as thermal deterioration of the resin. In addition, it is difficult to mix such a masterbatch with the remaining main raw material resin and the like during film extrusion to disperse the filler well. Especially in a transparent film, if "burnt" of the resin occurs when the filler is mixed, the transparency may be impaired and the product may not be viable.

[0004]

An object of the present invention is to solve the above-mentioned problems of the prior art. Specifically, in melt extrusion molding of a thermoplastic resin transparent film, a filler is dispersed well. The object of the present invention is to provide a manufacturing method for preventing blocking between films in the obtained product roll.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in melt extrusion molding of a thermoplastic resin film, a filler is previously fused with an additive and then melt extrusion molding is performed. By carrying out, it was found that a film in which the filler was well dispersed was obtained, and the present invention was completed.

That is, the present invention is characterized in that in a method of mixing a thermoplastic resin composition with a filler, melt-extruding it, and forming a film, the filler is fused with an additive and then mixed with the thermoplastic resin. The film manufacturing method is as follows.

The preferred embodiment of the present invention is as follows.

Preferred additives are stabilizers or UV absorbers.

The preferable average particle size of the filler is 0.
It is 001-10 micrometers.

The preferable content of the filler is based on the weight of the thermoplastic resin composition (including the filler).
It is 0.04 to 0.3% by weight.

The preferred coalescence method is to mix the filler and additive under high shear.

The term "fusion" as used herein means a state in which the particle size distribution of the mixture of the filler and the additive exhibits a substantially single peak, or the mixture of the filler and the additive obtained by the fusion method described in detail below. Refers to the state of.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Typical examples of the thermoplastic resin in the present invention include ester resins, amide resins, olefin resins, cyclic olefin resins, acrylic resins, maleimide resins, glutarimide resins, Examples thereof include vinyl resins and their copolymers. Further, two or more kinds of these thermoplastic resins may be blended.

The filler in the present invention is roughly classified into an organic filler and an inorganic filler. Examples of the organic filler include fine resin particles having acrylic acid, styrene, urethane and the like as constituent components, and the inorganic filler includes
Examples thereof include clay, mica, titanium oxide, calcium carbonate, wet silica and dry silica.

The additives in the present invention include flame retardants, stabilizers, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, antioxidants, pigments, dyes, etc., and have various shapes such as powder and flakes. However, depending on the fusion method adopted, powdery form may be preferable. In addition, the stabilizer and the ultraviolet absorber are generally small in the amount added to the resin and are less likely to significantly impair transparency even when used in the production of a transparent film, and thus are suitable as the additives of the present invention. The additives used for fusion may be used alone or in combination of two or more.

As a method of fusing the additive and the filler, the additive is heated and melted, the filler is added thereto and dispersed and mixed, and then the mixture is cooled and solidified and ground, or the additive is dissolved in a solvent, After adding and dispersing and mixing the filler, there are a method of evaporating the solvent and pulverizing, a method of mechanically fusing the filler to the surface of the additive by mixing the additive and the filler under high shear. However, a mechanical fusion method that has simple steps is particularly preferable.

As a device for mechanically fusing under high shear, a high-speed stirrer or a homogenizer can be used, and a ball mill, a crusher, or a dry powder such as a mechanofusion (R) device manufactured by Hosokawa Micron. A fusion device can also be used. Among these devices for mechanically fusing under high shear, a dry powder fusing device is particularly preferable.

The average particle size of the filler is from 0.001 μm to
10 μm, preferably 0.005 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm are used.
When the particle size of the filler exceeds 10 μm, obvious unevenness is recognized on the film surface, and haze becomes large, which is not preferable. When it is 0.001 μm or less, the unevenness of the surface becomes small and the effect of slipperiness becomes small, which is not preferable. The shape of the filler includes a spherical shape, a needle shape, a plate shape, and the like. In the present specification, the particle diameter of the needle filler means the minor axis diameter, and the particle diameter of the plate filler means the thickness. However, haze tends to decrease when a needle-shaped or plate-shaped filler is used, and
A spherical filler is preferable because the effect of preventing mutual adhesion (blocking) tends to be small.

The amount of the filler added is 0.04 to 0. 0, based on the weight of the thermoplastic resin composition (including the filler).
3% by weight, preferably 0.05 to 0.2% by weight, more preferably 0.05 to 0.15% by weight is used. 0.
If it exceeds 3% by weight, the haze of the film will increase,
When it is 0.04% by weight or less, the effect of slipperiness is reduced, which is not preferable.

If necessary, a flame retardant, a heat stabilizer, a plasticizer, a lubricant, an ultraviolet absorber, an antistatic agent, an antioxidant, a pigment, a dye, etc., may be separately added to the thermoplastic resin. Can be done.

The method of forming a film by the melt extrusion method is not particularly limited, but one of the preferred embodiments will be described below.

In a preferred embodiment, the thermoplastic resin composition used is pre-dried before being formed into a film. The preliminary drying is performed, for example, by using a hot air dryer or the like with the raw material in the form of pellets or the like. Pre-drying is very useful because it can prevent foaming of the extruded resin.
The pellets are then fed to the extruder. The thermoplastic resin composition heated and melted in the extruder is supplied to the T die through a gear pump and a filter. The use of the gear pump is very useful because it has a high effect of improving the uniformity of the resin extrusion amount and reducing the thickness unevenness. Further, the use of a filter is useful for removing foreign matters in the resin and obtaining a film having a good appearance without defects. In a further preferred embodiment, the sheet-shaped molten resin extruded from the T die is sandwiched between two cooling drums and cooled to form a film. It is particularly preferable that one of the two cooling drums is a rigid metal drum having a smooth surface, and the other is a flexible drum having an elastically deformable metal elastic outer cylinder having a smooth surface. .

[0023]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Method of measuring characteristics> Haze: Measured with a turbidimeter NDH-300A (Nippon Denshoku Industries Co., Ltd.). The average value of three 5 cm × 10 cm samples was used.

Static friction coefficient: SURFACE PROPE
RTY TESTER HEIDON-14DR (HEI
Measured by DON). Measure the friction between one side and the other side. The average value of three points of the sample was used.

Winding deviation: The deviation width of the end portion of the wound sample was measured. It is preferably 10 mm or less.

(Examples 1 to 9) 100 parts by weight of a pellet-type acrylonitrile-styrene copolymer was used as a filler and a stabilizer shown in Table 1 as mark AO-6 manufactured by Adeka Corporation.
0.2 parts by weight of 0 as an ultraviolet absorber, ADEKA CORPORATION
Add 1.0 parts by weight of ADEKA STAB 1413 made, blend with a tumbler, 40 mm extruder (L / D = 30)
Was extruded into pellets. The filler at this time was used after being mechanically fused (using a mechanofusion device manufactured by Hosokawa Micron Co., Ltd.) to an ADEKA STAB 1413 manufactured by ADEKA CORPORATION, which is an ultraviolet absorber. Using this raw material pellet, a 40 mm extruder (L / D = 24) was equipped with a connection pipe plated with hard chrome and a T-die to form a melt-extruded film.

The characteristics of the obtained film are shown in Table 2.

[0029]

[Table 1]

[0030]

[Table 2]

(Examples 10 to 13) Pelletized acrylonitrile-styrene copolymer was replaced with 100 parts by weight, and 65 parts by weight of a pelletized copolymer containing isobutene and N-methylmaleimide as a resin, and pelletized acrylonitrile.
Examples 1 to 9 except 35 parts by weight of styrene copolymer were used.
Raw material pelletization and melt extrusion film formation were carried out in the same manner as in. The characteristics of the obtained film are shown in Table 3.

[0032]

[Table 3]

Comparative Example 1 0.2 parts by weight of Mark AO-60 manufactured by Adeka Co., Ltd. as a stabilizer and 100 parts by weight of acrylonitrile-styrene copolymer in the form of pellets were manufactured by Adeka Co., Ltd. as an ultraviolet absorber. Add 1.0 parts by weight of ADEKA STAB 1413 and blend with a tumbler to 40
Extrusion pelletization was performed with a mm extruder (L / D = 30). A 40 mm extruder (L / D
= 24), a connection pipe plated with hard chrome and a T-die were attached to form a melt-extruded film. The characteristics of the obtained film are shown in Table 4.

Comparative Example 2 65 parts by weight of a pellet copolymer containing isobutene and N-methylmaleimide as a resin in place of 100 parts by weight of a pellet acrylonitrile-styrene copolymer and 35 pellet acrylonitrile-styrene copolymer 35 Raw material pelletization and melt extrusion film formation were carried out in the same manner as in Comparative Example 1 except that the weight part was used. The characteristics of the obtained film are shown in Table 4.

Comparative Example 3 Raw material pelletization and melt extrusion film formation were carried out in the same manner as in Example 1 except that the filler was not fused.

As a result, the raw material pellets could not be obtained because the filler could not be stably supplied during the pelletizing extrusion.

(Comparative Example 4) Raw material 5 in which 1% by weight of a filler was melt-mixed in advance with an acrylonitrile-styrene copolymer
The raw material pelletization and the melt extrusion film formation were performed in the same manner as in Example 1 except that the weight% and the untreated acrylonitrile-styrene copolymer 95% by weight were used (masterbatch method). The characteristics of the obtained film are shown in Table 4. The variation (R) in haze is large, indicating that the filler is not uniformly dispersed and mixed.

[0038]

[Table 4]

[0039]

Since the present invention has the above-mentioned structure, it has the following effects. That is, in the melt extrusion molding of the thermoplastic resin film, the filler is used after being pre-blended with the additive, so that the haze of the film is less reduced,
It is excellent as a method for producing a transparent film that does not cause mutual sticking (blocking) between films in the obtained product roll.

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Claims (5)

[Claims] 1. A method for producing a film, which comprises mixing a filler with a thermoplastic resin composition, melt-extruding the mixture, and forming a film, wherein the filler is fused with an additive and then mixed with the thermoplastic resin. . 2. The film manufacturing method according to claim 1, wherein the additive is a stabilizer or an ultraviolet absorber. 3. The average particle size of the filler is 0.001 to
The film manufacturing method according to claim 1 or 2, which has a thickness of 10 μm. 4. The content of the filler is 0.0 based on the weight of the thermoplastic resin composition (including the filler).
The film manufacturing method according to any one of claims 1 to 3, which is 4 to 0.3% by weight. 5. The method for producing a film according to claim 1, wherein the additive and the filler are fused by mixing the filler and the additive under high shear.