JP2001180854A - Clip travel device, orientation and heat treatment method of thermoplastic resin sheet using it and method of manufacturing thermoplastic resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clip travel device capable of successively orienting a thermoplastic resin in the lengthwise direction and the width direction in a noncontact state for the purpose of manufacturing an oriented thermoplastic resin sheet with zero surface defect, excellent easy surface slidableness and easy surface adhesive property as well as to provide a heat treatment device using the clip device, an orientation and heat treatment method of the thermoplastic resin sheet or a manufacturing method of the thermoplastic resin sheet. SOLUTION: This clip traveling, heat treatment device using this device, orientation and heat treatment device of a thermoplastic resin sheet or a manufacturing method of the thermoplastic resin sheet are featured by being constituted so that clips having a structure allowing free traveling on a rail are detachably constituted in clip driving devices arranged at least in two places, and the clips are forcedly made to travel on the rail by being installed in the clip driving devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clip traveling device, and more particularly to a clip traveling device for producing a stretched thermoplastic resin film having no surface defects and excellent in surface characteristics. The present invention relates to a method for stretching and heat-treating a thermoplastic resin sheet and a method for producing a thermoplastic resin sheet.

More specifically, in general, the film is generally provided in a heating oven, and runs on a pair of left and right rails while gripping both ends of the film to perform a stretching process, a relaxation process or a heat treatment at a fixed length. And a method for stretching and heat-treating a thermoplastic resin sheet and a method for producing a thermoplastic resin sheet using the same.

[0003]

2. Description of the Related Art Ordinary stretching in the production process of a thermoplastic resin film is carried out in a longitudinal direction using a roll and in a width direction using a tenter.

When performing uniaxial stretching or biaxial stretching only in the longitudinal direction, it is necessary to heat and stretch the sheet by bringing the sheet into contact with the roll. In this case, the peripheral speed of the roll must match the heated sheet speed. Instead, the surface of the roll is often scratched because the sheet slides on the roll.
For this purpose, efforts are made to adjust the roll peripheral speed, and the roll surface layer is cleaned so as not to damage the sheet, but in reality, a defect-free sheet cannot be obtained.

[0005] Therefore, it has been proposed to laminate a releasable resin sheet on the surface layer and stretch it. Alternatively,
There has been proposed a method using a simultaneous biaxial stretching machine that stretches in the longitudinal direction by gripping with a clip.

[0006]

However, in the method of laminating a releasable resin sheet (layer B) on the surface layer of the resin sheet (layer A) and stretching, the stretching is performed while another resin layer is laminated on the surface layer. -When heat-treated, even if additives such as a lubricant are contained, not only a smooth and smooth surface cannot be formed on the surface of the resin sheet after peeling, but also surface defects due to surface transfer of the resin B layer occur, There were fatal drawbacks such as the inability to coat the coating liquid in-line in film formation, the difficulty in detecting the thickness of the resin sheet A layer, and the difficulty in collecting only the resin to be laminated.

In addition, the simultaneous biaxial stretching machine requires a great deal of time, usually one or more days, to change the magnification in the longitudinal direction, so that it is practically impossible to change the magnification and the film forming speed is abnormal. However, it has a serious drawback in productivity such as a low maximum thickness of the sheet that can be stretched. In addition, a simultaneous biaxial stretching machine using a linear motor has been commercially available in recent years, but it is very expensive, the production cost is abnormally high, and there is a problem that it cannot be used for producing a general-purpose film.

In particular, the present invention is to provide a clip traveling device capable of successively stretching a thermoplastic resin in a longitudinal direction and a width direction without contact, and further provides a heat treatment device using the clip device. It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method which provide a method for stretching and heat treating a thermoplastic resin sheet, or a method for manufacturing a thermoplastic resin sheet.

[0009]

A clip traveling device according to the present invention which achieves the above object has the following constitutions (1) to (8). (1) A clip having a structure capable of free running on a rail is configured to be detachable from clip driving devices provided at at least two places, and the clip is
A clip traveling device, wherein the clip traveling device is configured to be forcibly traveling on a rail by being mounted on the clip driving device. (2) One of the clip driving devices at at least two locations runs at a predetermined linear velocity V ₀ , and the other clip driving device runs at a predetermined linear velocity V _1. The relationship between V ₀ and V ₁ is V ₀ = V ₁ , and the clip is run at the same linear velocity, and the clipped traveling body is fixed and heat-treated. The clip traveling device according to 1). (3) One of the clip driving devices at at least two places runs at a predetermined linear velocity V ₀ , the other clip driving device runs at a predetermined linear velocity V ₁ , The relationship between V ₀ and V ₁ is V ₀ > V ₁ , and as the clip advances, the clip is decelerated and traveled.
The clip traveling device according to the above (1), wherein the traveling object to be gripped by the clip is configured to be subjected to a relaxing heat treatment. (4) At least two clip driving devices, one of which runs at a predetermined linear velocity V ₀ and the other of which drives at a predetermined linear velocity V ₁ , and the linear velocities The relationship between V ₀ and V ₁ is V ₀ <V ₁ .
The clip traveling device according to the above (1), wherein the traveling body to be gripped by the clip is configured to extend in the longitudinal direction. (5) At least two clip driving devices are such that one clip driving device runs at a predetermined linear speed V ₀ and the other clip driving device runs at a predetermined linear speed V _1. The relationship between V ₀ and V ₁ is V ₀ <V ₁ .
The clip traveling device according to (1), wherein the traveling body to be gripped by the clip is configured to extend in the longitudinal direction and also in the width direction. (6) The above (1), (2), wherein the mechanism for attaching and detaching the clip to and from the clip driving device has a mechanism based on at least one or more actions selected from magnetic force, mechanical force, and electrostatic force. , (3), (4) or (5). (7) The clip attached to one clip driving device is
By changing the attachment to another clip drive device,
The traveling speed of the clips, from V ₀ to V _1, or when changing to the contrary, between V ₀ and V ₁ to the linear velocity is changed, the clip configured to freely travel on the rails The clip traveling device according to the above (2), (3), (4), (5) or (6), which is characterized by the following. (8) The clip attached to one clip driving device is
By changing the attachment to another clip drive device,
When the running speed of the clip is changed from V ₀ to V ₁ or vice versa, the clip is configured to run on the rail by torque driving until the linear speed is changed between V ₀ and V ₁ . (2), (3),
The clip traveling device according to (4), (5) or (6).

The heat treatment apparatus of the present invention that achieves the above object has the following configuration (9). (9) The above (1), (2), (3), (4), (5), (6), (7) or
(8) A heat treatment apparatus, comprising: the clip traveling device according to (8), wherein the object to be processed is gripped by the clip traveling device to perform a desired heat treatment.

Further, a method for stretching and heat-treating a thermoplastic resin sheet of the present invention which achieves the above object has the following constitution (10) or (11). (10) When stretching in the longitudinal direction of the thermoplastic resin sheet while gripping the edge of the sheet with a clip, the above (1), (2), (3), (4), (5), (5) A method for stretching and heat-treating a thermoplastic resin sheet, which is performed by the clip traveling device according to (6), (7) or (8). (11) When performing a fixed length treatment, a tension treatment or a relaxation heat treatment while holding the end of the thermoplastic resin sheet with a clip, the above (1), (2), (3), (4), (5), (5) 6), (7)
Or a method for stretching and heat-treating a thermoplastic resin sheet, which is performed by the clip traveling device according to (8).

Further, a method for producing a thermoplastic resin sheet of the present invention which achieves the above object has the following constitution (12). (12) The thermoplastic resin sheet discharged from the die is processed by using the method of stretching and heat-treating the thermoplastic resin sheet according to the above (10), (11), and is subjected to a stretching treatment, a fixed length treatment, a tension treatment or A method for producing a thermoplastic resin sheet, comprising producing a thermoplastic resin sheet by performing a relaxation treatment.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The inventors of the present invention have intensively studied a method of forming a resin sheet having no defect on the surface under conditions close to ordinary film forming conditions. As a result, at least two clips that can freely travel on the tenter rail are provided. It has been found that stretching and heat treatment using a clip traveling device capable of forcibly traveling on rails by being attached to and detached from a driving device is extremely effective. In the present invention, the clip device is generally provided in a heating oven, and runs on a pair of left and right rails while gripping both ends of the film,
It is used for performing a stretching treatment, a relaxation or a heat treatment at a fixed length. As a basic configuration, the clip traveling device of the present invention is configured such that a clip having a structure capable of freely traveling on a rail is detachable from a clip driving device provided at at least two places. By being attached to the clip drive,
It is configured so that it can be forcibly driven on a rail.

FIG. 1 is a schematic conceptual diagram showing an example of a schematic model structure of the clip traveling device according to the present invention. Has a basic structure in which the clip 2 can travel freely on the rail 3.
At least two clip driving devices are attached to and detached from the clip driving device so that they can be forcibly driven on rails.

In FIG. 1, reference numeral 4 denotes a low-speed rotation driving device and 5 denotes a high-speed rotation driving device. Even if the clip driving devices at at least two positions drive the clips at the same speed, respectively. Depending on the traveling direction of the rail, the speed may change from a low speed to a high speed as shown in FIG. 1 or vice versa.

In particular, in the case where there are two separate clip driving devices, each running at a linear speed of V ₀ and V ₁ , the clip runs at the same speed at a linear speed of V ₀ = V _1. are possible fixed heat treatment in the case of, or, in the case of the embodiment for deceleration as clip advances in the linear velocity of V _0> V ₁ may be the relaxation heat treatment, or even, V ₀ <V ₁
In a case where the linear speed is set to be higher and the speed of the clip is increased as the clip advances, the film can be stretched in the longitudinal direction. Stretching and heat treatment are performed using such a clip traveling device.

It is also possible to adopt a mode in which the linear speed V ₀ <V ₁ is satisfied and the speed is increased as the clip advances, and the tenter rail is widened so that the tenter rail is stretched simultaneously in the width direction and the longitudinal direction. is there. By using such a clip traveling device, the stretching ratio and the relaxation ratio in the longitudinal direction can be instantaneously changed as in the case of the roll stretching.

That is, when the oriented sheet is manufactured by stretching the thermoplastic resin sheet in the longitudinal direction and / or the width direction, the longitudinal direction or the heat treatment of the sheet edge is performed by using the clip of the clip traveling device. Thus, the film can be formed while instantaneously changing the stretching ratio or stretching ratio in the longitudinal direction.

In the present invention, the thermoplastic resin may be any resin that exhibits a melt flow upon heating, and is selected from polyesters, polyamides, polyolefins, polyphenylene sulfides, vinyl polymers, and mixtures and modified products thereof. Resin is a typical one.

In the present invention, the polyester is a high molecular compound having an ester bond in the molecular main chain, and includes, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, liquid crystal polyester, and copolymers thereof. Among them, polyethylene terephthalate, polyethylene naphthalate and a copolymer thereof are preferable, and polyethylene terephthalate and a copolymer thereof are particularly preferable.
The number of repeating units of these polymer compounds is 80 or more, preferably 120 or more. The intrinsic viscosity was determined to be 0.1 as a value measured in orthochlorophenol (OCP).
4 (dl / g) or more, preferably 0.55 (dl / g)
It is good to be above.

As a method for producing the polyester resin, a polymerization method that minimizes the residual amount of the metal catalyst is preferable. Specifically, not a transesterification method but a direct polymerization method in which polymerization is performed directly from a carboxylic acid is preferable. At this time, it is preferable that the polymerization catalysts such as germanium oxide and antimony oxide are as small as possible, and it is preferable that they do not contain magnesium oxide, manganese oxide, zinc oxide, aluminum oxide, etc. which are usually used as a transesterification catalyst.

Examples of the liquid crystal resin include polyester liquid crystal resin, polyester amide liquid crystal resin and polyamide liquid crystal resin. The composition is not particularly limited. In the present invention, polyester liquid crystal resin is particularly preferable. Such as aromatic diols,
It is a polyester liquid crystal polymer mainly composed of aromatic dicarboxylic acids such as terephthalic acid and naphthalenedicarboxylic acid, and hydroxycarboxylic acids such as parahydroxybenzoic acid and hydroxynaphthoic acid.Other than this, ethylene is an aliphatic diol. A liquid crystal resin containing a glycol or ether bond unit may be used, and these resins are characterized by having a regular structure even in a molten state.

These polyester resins can be used in combination with various additives, for example, resins such as a sliding agent, a stabilizer, an antioxidant, a viscosity modifier, an antistatic agent, a coloring agent, a pigment and a liquid crystal polyester. However, it is preferable that the additive be as small as possible.

The polyamide resin is a high molecular compound having an amide bond in the main chain. Typical examples thereof include nylon 6, nylon 66, nylon 610, nylon 12, nylon 11, nylon 7, nylon 7, / Paraxylylene adipamide, polyhexamethylene terephthalamide / isophthalamide, and their related copolymers, mixtures and the like.

The polyolefin resin includes polyethylene, polypropylene, methylpentene polymer, cyclic polyolefin, and copolymers and blends thereof with butene, hexene, vinyl acetate, and the like.・ Propylene butene C ₂ C ₃ C
₄ copolymers and the like are preferable, and a higher melt melt index (MI) of 4 to 15 (g / min) is preferable.

Various additives such as a slipping agent, a stabilizer, an antioxidant, a viscosity modifier, an antistatic agent, a coloring agent and a pigment can be used in combination with these resins. It is good to make an additive.

The clip traveling device according to the present invention is a clip traveling device in which a clip that can freely travel on a rail can forcibly travel on the rail by being attached to or detached from a clip driving device, and the speed increases as the clip travels. Or when deceleration is required, the speed of the first drive in the advancing direction should be V ₀ , at least two separate clip drives, and at least the speed of the drive ahead of the film in the advancing direction. Is V ₁ , the clip runs in synchronization with that speed, for example,
At the same linear velocity of V ₀ = V _1, the clip runs at the same speed at the start and end of biting of the film, so that a fixed heat treatment without dimensional change in the longitudinal direction becomes possible, and V ₀ >
Since deceleration in the longitudinal direction as the clip advances when the linear velocity of V _1, which is gripped by the clip film would be relaxed heat treatment in the longitudinal direction, the linear velocity of V ₀ <V ₁ in the opposite Then, as the clip advances, the running speed increases in the longitudinal direction, so that the film gripped by the clip is stretched in the longitudinal direction. of course,
With the linear velocity of V ₀ <V _1, the traveling speed is increased in the longitudinal direction as the clip advances, and the biaxial stretching can be performed simultaneously in both the width direction and the longitudinal direction by increasing the width of the tenter rail.

A mechanism for attaching and detaching a clip to such a clip driving device becomes important. For example, it is necessary to provide a gripping mechanism such as a magnetic force, a mechanical force such as a spring or a blade, and an electrostatic force. In particular, in the case of the present invention, the method of attaching and detaching all clips by a magnetic force using a magnet is the most excellent from the viewpoint of smooth attachment and detachment. However, since the apparatus is expensive and complicated, at least one clip driving device requires mechanical force. It is practical and practical to use the detaching method by using a mechanical force and a magnetic force together with other clip driving devices, such as a detaching method by a magnetic force.

Further, at a portion where the clip speed causes transfer from V ₀ to the linear velocity of V _1, the clip may be allowed to freely travel on the rails without applying external force, or the driving of the clip The vehicle may be driven on a rail by supplying torque drive.

By moving the clip while attaching and detaching the clip to and from such a plurality of clip traveling devices, the stretching ratio in the longitudinal direction of the thermoplastic resin sheet and the relaxation heat treatment rate in the longitudinal direction can be controlled by the relative speed of the individual driving devices. Can be easily changed in a very short time. That is, it is possible to instantaneously stretch while changing the stretching ratio in the longitudinal direction while holding the sheet end portion with the clip using the above-described clip traveling device, and also instantaneously change the relaxation rate as needed. In addition, the stretching heat treatment can be performed by changing the stretching ratio instantaneously or by performing a tension heat treatment on the thermoplastic resin sheet. By doing so, a film having no surface defect can be obtained by stretching, and a film having no physical property unevenness in the width direction and having no bowing phenomenon and a film having excellent thermal dimensional stability can be obtained by heat treatment.

In a pantograph-type simultaneous biaxial stretching production machine, changing the stretching ratio in the longitudinal direction requires a considerable amount of time, such as 24 hours or more, and it is practically impossible to change the stretching ratio in the longitudinal direction. Met. This involves operating the tenter at a high speed, and requiring many steps such as longitudinal stretching and transverse stretching, as well as heat treatment, thereby increasing the length of the tenter. This is because the number of clips is generally very large, such as 2,000 or more, so that a large amount of time is required to change the magnification. Of course, it is possible to change the magnification as described above even with the method of driving the clip by the linear motor drive using magnetic force, but the device becomes very complicated, the initial cost is abnormally high, and not only costs are high However, it has a major drawback in that repair time and costs for maintenance due to failures, etc. are not absurd.

By coating at least one surface of the thermoplastic resin sheet with a water-soluble or water-dispersible coating solution at any stage before and after stretching, the surface can be easily lubricated, easily adhered, antistatic, abrasion-resistant, etc. Characteristic can be imparted. As the resin used for the coating, an acrylic resin, a urethane resin, a polyester resin, a polyolefin resin, a polyamide resin, a urethane acrylic resin, a polyester urethane resin, and a resin or the like having a main component such as a copolymer or a blend thereof can be used. . As a coating method, any method such as a gravure roll, a metering bar, a reverse roll, and a die coater can be used.

Next, the clip traveling device according to the present invention,
A description will be given of an example of a method of stretching heat treatment of a thermoplastic resin sheet using the same.

A polyester resin is prepared as a thermoplastic resin. Various kinds of sliding materials, heat stabilizers, viscosity modifiers, antiblocking agents, coloring agents, antioxidants, various stabilizers and the like as polymer additives in the resin, and resin sheets obtained according to the present invention. Prepare raw materials etc. that are mixed with recovered raw materials, etc., and if necessary dry and dehydrate them,
After being heated and melted at a temperature not lower than the melting point of the resin in each extruder, the thermoplastic resin is extruded into a sheet shape from a T-die die, and a static charge application, an air knife, and a vacuum, which are conventional adhesion means. It is closely contacted with the cooling medium by a contacting means such as a chamber or a press roll and solidified by cooling. Of course, an appropriate filter, for example, a commonly used filter such as a sintered metal, a porous ceramic, a sand, or a wire mesh may be used to remove foreign matters of the resin in a molten state.

In order to stretch and heat-treat the thus obtained cast sheet at least in the longitudinal direction, the sheet is heat-stretched in the longitudinal direction while gripping the sheet end with the clip traveling device of the present invention. As this device, a clip traveling device is used in which a clip that can freely travel on the rail can be forcibly traveled on the rail by being attached to and detached from at least two clip driving devices. For example, two clip drive units each have the first clip V
_0, when the last clip is traveling at a linear velocity of V _1, as described above, or by stretching in the longitudinal direction in the linear velocity of V ₀ <V _1, further subsequently, the longitudinal stretched film It is supplied to a conventionally known width-direction stretching tenter and stretched in the width direction, or, at a linear velocity of V ₀ <V ₁ , the speed is increased as the clip advances,
By extending the clip in the width direction by expanding the clip in the width direction, simultaneous biaxial stretching can be performed at once. When heat treatment is performed before stretching, the linear velocity is set to V ₀ = V ₁ and fixed heat treatment without dimensional change is performed, or V ₀ >
In the linear velocity of V ₁ to deceleration as the clip progresses,
A relaxing heat treatment may be performed.

After the sheet is stretched in the longitudinal direction without contact in this manner, the sheet is once removed from the clip, and the irregular portion of the end gripped by the clip is cut, and the clip is gripped by another new stenter clip. The sheet is stretched and heat-treated in the width direction to produce a thermoplastic resin sheet. Preferably, the stretching temperature is equal to or higher than the glass transition temperature of the thermoplastic resin, and the stretching ratio is 3 to 7 in the longitudinal direction and the width direction, respectively.
It is about twice. Before or after the longitudinal stretching, at least one surface may be coated with a coating solution containing a lubricant in an aqueous solution or an aqueous dispersion of an acrylic resin or a urethane resin in order to impart lubricity or adhesiveness.

Further, in order to provide dimensional stability, the tree
Heat treatment near the melting point of the fat, usually after stretching in the width direction
After that, heat treatment is often performed with a tenter as it is. I
However, in the case of the present invention, the film after stretching in the width direction is
Re-clip with the clip traveling device,
Initial velocity V₀Clipping speed V ₁
So-called V₀> V₁Of linear velocity
Relaxation heat treatment in the longitudinal direction becomes possible. Rice cake
The width direction relaxes the tenter width as before
This is possible.

The thermoplastic resin sheet thus formed has not only a defect-free surface, easy lubricity and transparency, but also strength, heat resistance, low coefficient of linear expansion, insulation, low water absorption, high gas barrier properties, and the like. Since it has various characteristics,
It can be used for various applications such as magnetic recording medium sheets, packaging applications, and electrical insulation applications.

[0040]

[Measurement method of physical properties] Next, the method of measuring physical properties used in the present invention will be described below. 1. Thermal properties (Tm, Tg, Tmc) Using a DSC-II type measuring device manufactured by PerkinElmer, sample weight 10 mg, heating rate 20 ° C. /
The temperature at which the deviation of the baseline started was Tg, the exothermic peak at the further increase in temperature was Tcc, and the endothermic peak temperature accompanying crystal melting was the melting point Tm.
After holding at Tm + 20 ° C. for 1 minute, the melt was cooled at a cooling rate of 20 ° C./min.
mc.

[0041]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples for better understanding of the present invention. Example 1 A guide rail in which a clip can freely travel is provided in a heating oven, and a device for driving the clip near the guide rail is rotationally driven along the guide rail, and each device has a magnetic force. The clip drive device has a detachable device that allows the clip to be attracted and adhered by the magnetic force of the rotary drive member, and can be separated and detached as necessary. In addition, in this device, when changing to another clip driving device, a free running system without any driving was used.

Further, an experiment was carried out using a sample film made of an unstretched polyester film and using the above-mentioned apparatus. If speeding up or deceleration was required as the clip traveled, at least two separate clips were required. Assuming that the speed of the first drive in the advancing direction is V ₀ , and the speed of the first drive in the advancing direction of the film is V ₁ , the clip travels in synchronization with the speed. For example, if the linear velocity is equal to V ₀ = V _1, the clip runs at the same speed at the start and end of biting of the film, so that a fixed heat treatment without dimensional change in the longitudinal direction is possible, and V ₀ > V ₁ At a linear velocity of, the more the clip is advanced, the slower it runs in the longitudinal direction, so that the film gripped by the clip is subjected to relaxing heat treatment in the longitudinal direction. , Since accelerated running in the longitudinal direction as V ₀ <a clip when the linear velocity of V ₁ proceeds in the opposite,
It was confirmed that the film held by the clip was stretched favorably in the longitudinal direction.

Further, the linear velocity V ₀ <V ₁ can be set so that the linear speed is increased in the longitudinal direction as the clip advances, and the biaxial stretching is simultaneously performed in the width direction and the longitudinal direction by increasing the width of the tenter rail. I was able to confirm that I could. Example 2 Using polyethylene terephthalate (PET) (direct continuous polymerization method using 55 ppm of polymerization catalyst antimony trioxide), the PET resin was dried at 180 ° C. for 2 hours under vacuum. The resin was supplied to a usual single screw extruder, melted at 285 ° C., and extruded from a T-die die into a sheet. In order to bring the molten sheet into close contact with a casting drum, which is a moving cooling medium maintained at 25 ° C., 10 k
A static charge of V was applied to the drum and the drum was rotated at 10 m / min. The sheet thus obtained is heated to 90 ° C. in a state where the sheet end is gripped by the clip by the clip traveling device having the function of the first embodiment,
It was stretched 4.5 times in the longitudinal direction and cooled to room temperature. After cutting the end portion of the longitudinally stretched film, the central portion is supplied to another widthwise stretching stenter and heated to 95 ° C. so that the width of
Stretched twice and cooled to around 60 ° C once, then 220 ° C
The product was cooled to 160 ° C., relaxed by 5% in the width direction at this temperature, detached from the stenter clip, and slit at both edges to obtain a central product part.

The biaxially oriented PET having a width of 5 m thus obtained.
The thickness of the resin sheet was 188 μm, there was no foreign matter or defect on the PET surface or inside, it was a non-colored and highly transparent sheet, and the winding property was excellent. Comparative Example 1 In place of the tenter-type longitudinal stretching machine used in Example 2, the film was stretched and heat-treated in the same manner as in Example 2 except that the film was stretched using a commonly used roll-type longitudinal stretching machine. Was obtained. Since the surface of the sheet obtained in this manner was found to have surface defects such as scratches, transfer patterns, and scratches, it could not be used for severe applications such as optical applications. Example 3 Polyethylene naphthalate (PEN) was used as a raw material, and dried at 180 ° C. for 2 hours in a vacuum. The resin is fed to a usual single screw extruder and melted at 295 ° C.
The sheet was extruded from a die die into a sheet. 25 pieces of the molten sheet
In order to adhere to a casting drum, which is a moving cooling medium maintained at a temperature of 12 ° C., an electrostatic charge of 12 kV was applied from a tape-shaped electrode to adhere to a drum rotating at 40 m / min and solidify by cooling. 4. The sheet thus obtained is heated to 130 ° C. by a normal roll-type longitudinal stretching machine, and
The film was stretched 5 times and cooled to room temperature. The longitudinally stretched film was supplied to a widthwise stretching stenter, heated to 155 ° C. and stretched five times in the widthwise direction, and the biaxially stretched sheet was removed from the stenter. Subsequently, the end of the sheet was gripped by the clip of the clip traveling apparatus used in Example 1, and the clip traveling at an initial speed of 220 m / min was gripped in a tenter heated to 230 ° C., and then heated to 185 ° C. In the tenter, a 5% relaxation in the width direction was performed, and the outlet speed was reduced to 200 m / min to perform a relaxation heat treatment in the longitudinal direction. Thereafter, the sheet was cooled to 135 ° C. and the sheet was taken out from the tenter.

The thickness of the biaxially oriented PEN resin sheet thus obtained was 38 μm, there was no foreign matter or defect on the surface and inside of the PEN sheet, and the Young's modulus in the longitudinal and width directions was 8/8 Gpa. The heat shrinkage at 150 ° C. in the direction and width direction was as small as 0.1 / 0.1%, and the sheet had both rigidity and thermal dimensional stability. Comparative Example 2 Instead of the heat treatment tenter used in Example 3, using a conventional width-direction stretching tenter, heat-treated at 230 ° C. without removing the clip as it was.
% Relaxed heat treatment. The sheet thus obtained has a Young's modulus in the longitudinal and width directions of 8/8 Gpa, and a heat shrinkage at 150 ° C. in the longitudinal and width directions of 1.1 / 0.3.
%, And only a sheet having rigidity but poor thermal dimensional stability was obtained.

[0046]

According to the present invention, a clip traveling device capable of successively stretching a thermoplastic resin in a longitudinal direction and a width direction in a non-contact manner, and a stretch-heat-treated thermoplastic resin film having no surface defects and excellent surface properties using the same. Is provided.

[Brief description of the drawings]

FIG. 1 is a schematic conceptual diagram illustrating an example of a schematic model structure of a clip traveling device of the present invention.

[Explanation of symbols]

 1: Clip traveling device 2: Clip 3: Rail 4: Low-speed rotation driving device 5: High-speed rotation driving device

Claims (12)

[Claims] A clip having a structure capable of freely traveling on a rail is configured to be detachable from clip driving devices provided at at least two places, and the clip is mounted on the clip driving device. A clip traveling device characterized in that the clip traveling device is configured to be forcibly traveling on a rail. 2. A clip drive device at at least two places, one of which runs at a predetermined linear velocity V ₀ , and the other of which runs at a predetermined linear velocity V _1. The relationship between the linear velocities V ₀ and V ₁ is V ₀ = V ₁ , and the clip is run at the same linear velocity, and the gripped traveling body is fixedly heat-treated by the clip. The clip traveling device according to claim 1. 3. A clip drive device at at least two places, one of which runs at a predetermined linear velocity V ₀ and the other of which runs at a predetermined linear velocity V _1. The relationship between the linear velocities V ₀ and V ₁ satisfies V ₀ > V ₁ , and the clip is decelerated as the clip advances, so that the gripped traveling body is relaxed and heat-treated by the clip. The clip traveling device according to claim 1, wherein: 4. At least two clip driving devices are arranged such that one clip driving device runs at a predetermined linear velocity V ₀ and the other clip driving device runs at a predetermined linear speed V _1. The relationship between the linear velocities V ₀ and V ₁ is V ₀ <V ₁ , and the clip is made to travel at an increased speed as the clip advances, so that the traveling body to be gripped by the clip is extended in the longitudinal direction. The clip traveling device according to claim 1, wherein: 5. At least two clip driving devices are arranged so that one clip driving device runs at a predetermined linear velocity V ₀ and the other clip driving device runs at a predetermined linear speed V _1. The relationship between the linear velocities V ₀ and V ₁ is V ₀ <V ₁ , and as the clip advances, the clip is caused to travel at an increased speed so that the traveling body to be gripped by the clip is extended in the longitudinal direction and also in the width direction. The clip traveling device according to claim 1, wherein the clip traveling device is configured to be stretched. 6. A mechanism according to claim 1, wherein the mechanism for attaching and detaching the clip to and from the clip driving device has a mechanism based on at least one action selected from magnetic force, mechanical force, and electrostatic force. The clip traveling device according to 3, 4, or 5. 7. The clip is mounted on one of the clip actuator, by mounting changed to another one clip actuator, the traveling speed of the clips, to V ₁ from V _0, or changing to the opposite in claim 2, 3, 4, 5, characterized in that up to the clip that is configured to freely travel on the rail linear velocity is changed between V ₀ and V ₁
Or the clip traveling device according to 6. 8. A clip attached to one of the clip actuator, by mounting changed to another one clip actuator, the traveling speed of the clips, to V ₁ from V _0, or changing to the opposite in, V ₀ and between V ₁ to the linear velocity is changed, the clip according to claim 2, characterized by being configured so as to run on the rails with a torque drive,
7. The clip traveling device according to 3, 4, 5, or 6. 9. A clip traveling device according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the object to be processed is gripped by the clip traveling device to perform a desired heat treatment. A heat treatment apparatus characterized in that: 10. The clip of claim 1, 2, 3, 4, 5, 6, 7, or 8 when stretching the thermoplastic resin sheet in the longitudinal direction while gripping the end of the sheet with the clip. A method for stretching and heat treating a thermoplastic resin sheet, wherein the method is performed by a traveling device. 11. A fixed length treatment, a tension treatment or a relax heat treatment while gripping an end portion of a thermoplastic resin sheet with a clip.
Or a method for stretching and heat-treating a thermoplastic resin sheet, wherein the method is performed by the clip traveling device described in 8. 12. A thermoplastic resin sheet discharged from a die using the method for stretching and heat-treating a thermoplastic resin sheet according to claim 10 or 11, wherein a stretching treatment, a fixed length treatment, a tension treatment or a relaxation treatment is carried out. A method for producing a thermoplastic resin sheet, comprising: treating to produce a thermoplastic resin sheet.