JP3201167B2 - Thermoplastic resin film roll and method for producing 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 film roll formed by winding a thin and smooth thermoplastic resin film.

More specifically, the present invention relates to a thermoplastic resin film roll capable of preventing the occurrence of "wrinkles" due to a temperature shock by reducing the porosity between the films of the film roll.

[0003]

2. Description of the Related Art As a film roll, there is known a film roll in which the relationship between the center line average roughness (Ra) of the film and the winding hardness is within a specific range (for example, Japanese Patent Application Laid-Open No. Sho.
7-193322). When the film thickness exceeds 10 μm, deformation due to expansion or contraction of air between the film layers is small, and “wrinkles” due to a temperature shock hardly occur. However, when the film thickness is 10 μm or less, the occurrence of “wrinkles” due to a temperature shock becomes remarkable, and particularly when the film thickness is 8 μm or less, “wrinkles” occur even at a temperature change of about 10 ° C.

[0004] Further, the film surface roughness (SRa) is 0.1.
When the thickness exceeds 012 μm, air bleeding during film winding becomes good, and the porosity between film layers can be easily reduced by adding conventional lubricant particles. But,
If the thickness is less than 0.012 μm, air bleeding during film winding deteriorates remarkably, and the porosity between film layers increases. In particular, with a film having a thickness of 0.008 μm or less, “wrinkles” occur during winding.

[0005]

The above-mentioned conventional film roll prevents wrinkles from occurring with time, but in the course of film distribution, the film is placed in various environments in the form of a roll, and particularly abruptly. The change in temperature causes expansion or contraction of the air between the films, causing wrinkles (hereinafter referred to as "wrinkles" due to temperature shock). For this reason, the film roll may not be used for film processing in a later step. For example, when a wrinkled film roll is used as a base film for a magnetic recording medium that requires strictly flatness of the film, uneven application of the magnetic layer is caused in the process of manufacturing the magnetic tape, and the yield is significantly reduced. In addition, when used as a film for a capacitor, there are various problems such as a surface defect at a wrinkled portion remarkably deteriorating electric characteristics. As a method of preventing "wrinkles" due to such a temperature shock, packing materials such as covering a film roll with a material having low thermal conductivity have been dealt with, but in recent years, from the viewpoint of industrial waste, which has become a problem. Therefore, measures using film rolls are desired. An object of the present invention is to solve such a problem and to provide a film roll in which “wrinkles” hardly occur due to a temperature shock.

[0006]

According to the present invention, there is provided a film roll comprising a thermoplastic resin film having a film thickness of 10 μm or less and a film surface roughness (SRa) of 0.012 μm or less. And a thermoplastic resin film roll having a film interlayer porosity of 1.5 to 2.8%.

The thermoplastic resin used in the present invention is not particularly limited, and specific examples thereof include polyester, polyamide, polyolefin, and polyphenylene sulfide. Polyester, particularly, ethylene terephthalate, ethylene α, β-bis ( In the case of a polyester containing at least one structural unit selected from 2-chlorophenoxy) ethane-4,4'-dicarboxylate and ethylene-2,6-naphthalate units as a main component, the polyester resin of the present invention may be used. It is desirable because the effect becomes remarkable. In addition, within the range which does not inhibit the present invention, 2
More than one kind of resin may be mixed, or a copolymer may be used.

The thermoplastic resin of the present invention may or may not contain particles. If no particles are contained, a method of forming projections of the crystallized thermoplastic resin on the film surface is used. It is preferable to contain particles from the viewpoint of easy surface formation. At this time, the type of the particles is not particularly limited, but preferably has a spherical particle shape. Specifically, the particle size ratio (major axis / minor axis) of the particles is 1.0 to 1.0.
1.2, preferably 1.0 to 1.1, more preferably 1.0 to 1.05. If the particle size ratio is too large, voids are likely to be formed around the particles,
It is difficult to maintain the flatness of the film surface, which is not preferable. The particles are desirably organic particles. Specifically, there are particles made of a crosslinked polymer (for example, crosslinked polystyrene) and the like. In particular, the temperature at the time of weight loss by 10% (measured using a thermogravimetric analyzer Shimadzu TG-30M in nitrogen).
In the case of crosslinked polymer particles in which the degree of crosslinking is increased until the temperature rise rate (20 ° C./min) becomes 380 ° C. or more, it is desirable from the viewpoint of film durability.

As a method of winding the above-mentioned thermoplastic resin film into a roll, there are a center wind method and a surface wind method. To obtain the roll of the present invention, either method may be used. It is more preferable to use a surface wind system in which the contact pressure during winding can be controlled. The winding conditions are not particularly limited, but the following conditions are preferably used.

[0010] Winding tension 8-12 kg / m, winding contact pressure 30-6
0 kg / m, winding speed 100 to 200 m / min.

[0011] Among them, a width of 1 m or more and a length of 1.0 × 10 ⁴ m
When winding the above film, the winding tension is 10 to 12
Kg / m, winding contact pressure 40-60 kg / m, winding speed 130-18
It is preferable to set the range to 0 m / min.

The rolled thermoplastic resin film is
It is extremely effective for the film interlayer porosity to be 1.5% or more and 2.8% or less, preferably 1.5% or more and 2.5% or less to prevent "wrinkles" from occurring due to temperature shock. Films having an interlayer porosity of less than 1.5% are not preferred because blocking between films is likely to occur. Further, when the film interlayer porosity exceeds 2.8%, "wrinkles" are generated due to temperature shock, which is not preferable.

[0013]

【Example】

[Method for Measuring Physical Properties and Method for Evaluating Effect] The method for measuring characteristic values and the method for evaluating effect according to the present invention are as follows.

(1) Particle Size Ratio The polyester is removed from the film by plasma low-temperature incineration to expose the particles. The processing conditions are selected such that the polyester is ashed but the particles are not damaged.
This was scanned with a scanning electron microscope (Elionix ESM32).
00), and the image of the particles is processed by an image analyzer (IBAS2000 manufactured by Carl Zeiss).

In this measurement, the ratio of the major axis to the minor axis of each particle shown by the following equation is obtained, and the particle diameter ratio “average major axis / minor axis” is calculated from these values.

Long / short diameter ratio of individual particles = D1 / D2 where D1 is the long diameter (maximum diameter) and D2 is the short diameter (minimum diameter).

Particle size ratio = Σ (D1i / D2i) / N D1i and D2i are the major axis (maximum diameter) and minor axis (minimum diameter) of each individual particle, and N is the number of counted particles.

(2) Average diameter of particles The equivalent diameter of each area circle is determined for the particles counted in the measurement of (1), and the following numerical processing is performed on the number of particles of 5,000 or more by changing the observation position. The number average diameter D is determined by the following equation.

D = ΣDi / N where Di is the diameter of a particle equivalent to the area circle, and N is the number of counted particles.

The number average diameter D thus obtained is defined as the average particle diameter.

(3) Content of Particles A solvent in which the polyester is dissolved and the particles are not dissolved is selected, the particles are centrifuged from the solvent, and the amount of the particles is calculated as a ratio (% by weight) to the whole.

(4) Film surface roughness (SRa) A three-dimensional fine shape measuring instrument (model ET-30H) of Kosaka Laboratory
K) and a three-dimensional surface roughness analysis system (model MARM)
EC-3D) was used to measure the three-dimensional surface roughness (center plane average roughness). The conditions were as follows, and the value was an average value of 20 measurements.

• Tip radius of the stylus: 0.5 μm • Load of the stylus: 4 mg • Vertical magnification: 50,000 times • Lateral magnification: 200 times • Cutoff: 0.25 mm • Feed pitch: 5 μm • Measurement length: 500 μm・ Measurement area: 0.197 mm ²・ Measurement speed: 100 μm / sec (5) Porosity between film layers of roll The area of the end face of the rolled-up film roll and the film thickness,
It is calculated from the winding length by the following equation (1).

[0024]

(Equation 1) T: film thickness (μm) L: film winding length (m) Rd: film roll diameter (mm) Cd: winding core diameter (mm) (6) Evaluation of “wrinkles” due to temperature shock And left for 7 days at a humidity of 80%, and after confirming that "wrinkles with the passage of time" did not occur, the wafer was transported to a temperature of 10 ° C. and a humidity of 80%, left for 6 hours, and then subjected to a temperature shock. The presence or absence of "wrinkles" was confirmed.

The film roll is heated at a temperature of 5 ° C. and a humidity of 6
After leaving it for 5 days under the condition of 5% and confirming that there is no "wrinkle with the passage of time", it is transported under the condition of a temperature of 25 ° C. and a humidity of 65%, and left for 6 hours. Was confirmed. The "wrinkles" were all visually confirmed.

(7) Film Roll Hardness A 1 kg weight was attached to a Shimadzu Rubber Hardness Tester 200 manufactured by Shimadzu Corporation, and 10 points in the width direction of the film roll were measured, and the average value was taken as the hardness.

Examples 1 and 2 Crosslinked divinylbenzene / styrene copolymer particles having an average particle diameter of 0.3 μm, a particle diameter ratio of 1.03 and an average particle diameter of 0.8 μm, and a particle diameter ratio of 1.05 were added as additives. Polyethylene terephthalate containing .15% by weight and 0.01% by weight was prepared (thermoplastic resin A).

The thermoplastic resin A was melt-extruded from an extruder and cast on a cooling roll via a slit die to obtain an unstretched sheet. This unstretched film was stretched 4.0 times in the longitudinal direction at 90 ° C. 3. The uniaxially stretched film is stretched in the width direction using a tenter at the same temperature as in the longitudinal stretching.
After stretching twice, further stretching at 150 ° C. in the longitudinal direction, and then heat-treating at 180 ° C. for 5 seconds under a constant length, the film thickness is 7 μm, and the film surface roughness (SRa) is 0.010 μm.
And film thickness 4μ, film surface roughness (SRa)
Of a thermoplastic resin film having a thickness of 0.011 μm.
This film was wound on a film roll having a width of 1 m and a length of 10,000 m at a winding tension of 10 kg / m, a winding contact pressure of 50 kg / m, and a winding speed of 150 m / min by a surface center wind type slitter. Table 1 summarizes the porosity, hardness, and "wrinkle" generation state due to temperature shock of each film roll.

Comparative Example 1 Colloidal silica particles having an average particle diameter of 0.3 μm, a particle diameter ratio of 1.05 and an average particle diameter of 0.8 μm, and a particle diameter ratio of 1.05 were 0.3% by weight and 0.1%, respectively, as additives. Polyethylene terephthalate containing 02% by weight was prepared (thermoplastic resin B).

Using this thermoplastic resin B, a film thickness of 7 μm and a film surface roughness (SR
a) A thermoplastic resin film having a thickness of 0.010 μm was obtained. This film was slit under the same conditions as in Example 1 to obtain a film roll. Table 1 summarizes the porosity, hardness, and "wrinkle" generation state due to temperature shock of each film roll.

Comparative Example 2 0.3% by weight of colloidal silica particles having an average particle diameter of 0.3 μm and a particle diameter ratio of 1.05 as additives and an average particle diameter of 0.8
μ, 0.01% by weight of calcium carbonate particles having a particle size ratio of 1.3
Was prepared (thermoplastic resin C). Using this thermoplastic resin C, a raw thermoplastic resin film having a film thickness of 7 μm and a film surface roughness (SRa) of 0.010 μm was obtained under the same conditions as in Example 1. This film was slit under the same conditions as in Example 1 to obtain a film roll. Table 1 summarizes the porosity, hardness, and "wrinkle" generation state due to temperature shock of each film roll.

Comparative Example 3 Polyethylene terephthalate containing 0.1% by weight of aggregated silica particles having an average particle diameter of 0.4 μm and a particle diameter ratio of 1.5 was prepared as an additive (thermoplastic resin D).

Using this thermoplastic resin D, a film thickness of 7 μm and a film surface roughness (SR
a) A thermoplastic resin film having a thickness of 0.010 μm was obtained. This film was slit under the same conditions as in Example 1 to obtain a film roll. Table 1 summarizes the porosity, hardness, and "wrinkle" generation state due to temperature shock of each film roll.

The thermoplastic resin film rolls of Examples 1 and 2 satisfying the requirements of the present invention did not have "wrinkles" caused by temperature shock as shown in Table 1, whereas those of Comparative Examples 1 to 3 did not. The plastic resin film roll is an example that does not satisfy the requirements of the present invention, but "wrinkles" are generated due to a temperature shock.

[0035]

[Table 1]

[0036]

As described above, the thermoplastic resin film roll of the present invention, which is a conventional thin film and smooth film, can avoid deterioration in quality due to environmental changes, and has high industrial value.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 18/28 B29C 55/02 B65H 23/18 B29K 105: 16

Claims (5)

(57) [Claims] 1. A film thickness of 10μm or less, the surface roughness of the film (SRa) is in a film roll of the following thermoplastic resin film 0.012 .mu.m, the Fi
Film layers porosity of Lum roll of 1.5 or more, 2.8
% Of a thermoplastic resin film roll. 2. The thermoplastic resin film roll according to claim 1, wherein the film contains spherical organic particles. 3. The thermoplastic resin film roll according to claim 2 , wherein the spherical organic particles are spherical crosslinked polystyrene particles. 4. A winding tension of 8 to 12 kg / m and a winding contact pressure of 3
The method for producing a thermoplastic resin film roll according to any one of claims 1 to 3, wherein the film is wound at a winding speed of 0 to 60 kg / m and a winding speed of 100 to 200 m / min. 5. A film having a width of 1 m or more and a length of 1.0 × 10 ⁴ m or more at a winding tension of 10 to 12 kg / m, a winding contact pressure of 40 to 60 kg / m, a winding speed of 130 to 180 m / min. The method for producing a thermoplastic resin film roll according to any one of claims 1 to 3, wherein the film is wound.