JP2000158455A - Heat insulation wall plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give no surface fault to a treated film by incorporating a surface layer in a photocatalyst layer, scarcely depositing an impurity, a foreign matter or the like on a wall plate surface layer and decomposing it even when deposited. SOLUTION: A photocatalyst layer on a surface layer changes water and oxygen into active oxygen by oxidizing and reducing operations by emitting a light, and decomposes an organic material and an inorganic material into a carbonic acid gas and water. As the photocatalyst, oxide, carbide or sulfide of a transition metal such as TiO2, WO3, SiC, MoS2 or the like is used. A sol liquid of titanium oxide, silicon oxide, Teflon, titanium peroxide or the like with a binder is sprayed on a partition wall plate body or baked and solidified after impregnating, or flame-coated with titanium oxide powder directly or after mixing with other ceramics, or metal titanium is oxidized on its surface layer by anodizing or surface oxidizing or the like to form a titanium oxide layer. Thus, it is less necessary to periodically clean the plate. The layer is used on the plate of a heater to avoid giving a fault to a surface of a resin film made of a thermoplastic resin or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stretching and heat-treating a film or the like made of a thermoplastic resin or a thermosetting resin.
The present invention relates to a novel heat retaining wall plate that can be used in a heating process such as distortion removal, cross-linking, and transport, and a film heat treatment apparatus using such a heat retaining wall plate.

[0002]

2. Description of the Related Art In a process such as stretching, heat treatment, strain relief, cross-linking, and transport of a thermoplastic resin film, the film is often heated, but this is done by heating an oven or the like partitioned by partition walls. It was usual to use equipment.

[0003]

In order to stretch, heat-treat, strain-relieve, crosslink, and convey a film, it is necessary to heat the film to a temperature higher than the glass transition temperature or higher than the reaction temperature. Unreacted compounds such as monomers and oligomers contained in the film, volatile additives and solvents are scattered, and as a result, adhere to the partition walls of the oven and the like, and the adhered substances fall onto the treated film. There is also a serious problem that the film may be soiled or torn during stretching.

The present invention has been made in view of the above-mentioned problems, and it is difficult to deposit impurities and foreign substances on the surface layer of a wall plate such as a partition wall. It is an object of the present invention to provide a partition plate which does not cause various surface defects on the treated film.

[0005]

According to the present invention, there is provided a partition wall plate having a photocatalyst layer on a surface layer.

Further, the heat insulating wall plate of the present invention further provides a film heat treatment apparatus using the heat insulating wall plate as a heating means for a film to be processed. A method for producing and processing a film, characterized in that the film is subjected to a heat treatment by using it as a heating means for the treated film.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The partition wall plate for heat retention according to the present invention has a photocatalyst layer on a surface layer. Here, the photocatalyst layer means water by oxidation / reduction by irradiation of light. It has the function of converting oxygen and oxygen into active oxygen and decomposing organic and inorganic substances into carbon dioxide and water. As the photocatalyst layer, transition metal oxides, carbides, sulfides, and the like often exhibit the characteristics, but typical compounds include TiO _2, SrTiO _3, WO _{3, and} Fe ₂ O.
₃ , Bi ₂ O ₃ , ZnO, SnO _2, CdS, SiC,
There are CdSe, MoS ₂ , CdTe and the like, and the most typical compound is titanium oxide, and among the crystal systems of titanium oxide, the anatase type exhibits its effect particularly.

As a method for forming such a compound having a photocatalytic function on the surface of the partition plate, a sol solution of titanium oxide and a binder (silicon oxide, Teflon, titanium peroxide, etc.) is sprayed on the base material of the partition plate or impregnated. After that, a method of firing and fixing, a method of spraying titanium oxide powder directly or after mixing with other ceramics, or a method of oxidizing the surface layer by anodic oxidation or surface oxidation of titanium metal to form a titanium oxide layer There is a method to form
It can be used properly depending on the purpose and effect. Furthermore, it is also possible to spray silver ions or copper ions onto these titanium oxide layers or to form a layer containing silver or copper metal ions after spraying silver ions or copper ions when forming the titanium oxide layers. is there. Particularly when high photoactivity is required, if titanium peroxide is used as the binder, the binder is changed to titanium dioxide by heat treatment at 200 ° C. or more, and the photoactivity is increased.

Although the thickness of the photocatalyst layer is not particularly limited, it may basically be a thin layer of about 0.1 μm to several tens μm, but is determined in consideration of the adhesive strength, surface roughness, mechanical strength and the like. It is good to do. The intensity of the ultraviolet light to be irradiated is preferably about 1 to 5 × 10 ³ mW / cm ² , but the stronger the ultraviolet light intensity, the greater the photocatalytic ability and its effect.

Next, it is preferable that the surface temperature of the partition plate having the photocatalyst layer of the present invention is kept at 150 ° C. or lower, preferably 100 ° C. or lower. This seems to be better at high temperature in view of the reaction temperature, but after various investigations, it is actually the opposite, and according to various findings of the present inventors, the temperature of the partition plate is 150 ° C. or less. , Preferably 100 ° C
The lower one, the greater the effect. Although the reason for this is not necessarily clear, it is better to lower the temperature of the partition wall plate, unreacted compounds such as monomers and oligomers, volatile additives,
It is considered that a solvent or the like easily deposits on the partition plate, which is likely to be decomposed by a photocatalytic reaction.

By using a partition plate having a photocatalyst layer on the surface of a partition plate for a heating device such as an oven in this way, a manufacturing process such as heating, heat treatment, distortion removal, crosslinking, and transport of a film of a thermoplastic resin or the like can be performed. Even when used in a processing step or a processing step, a film can be obtained in which the partition plate is not stained with time and has no defect on the surface of the resin film.

The method of use is basically the same as the method of using a partition wall plate which has been conventionally used. However, in the case of the heat retaining partition wall of the present invention, particularly, in order to increase the catalytic effect, 400 nm is used.
It is more preferable to use ultraviolet rays while irradiating the following ultraviolet rays directly to the partition plate perpendicularly, or while irradiating the same in parallel from the end face of the photocatalyst layer, and more preferably under humidification.

The thermoplastic resins that can be used in carrying out the present invention include polyethylene, polypropylene,
Various polyolefin resins such as polymethylpentene,
Polyamide resins such as nylon 6, nylon 66, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene-2,6-naphthalate (PEN), polybutylene naphthalate (PB)
N), polytrimethylene terephthalate (PPT), polyethylene-p-oxybenzoate, poly-1,4-
Cyclohexylene dimethylene terephthalate (PC
T) and as a copolymerization component, for example, a diol component such as diethylene glycol, neopentyl glycol, and polyalkylene glycol; and a dicarboxylic acid component such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Various polyester resins such as polyesters obtained by copolymerizing the above-mentioned compounds, polyacetal resins, polyphenylene sulfide resins, and the like can be used. In particular, in the present invention, when a polyester resin is used, its effect is high and preferable. Among them, polyethylene-2,6-naphthalate (PEN)
A resin having low crystallinity such as polyethylene or polyethylene terephthalate (PET) is preferable. In particular, polyethylene terephthalate (PET) is used in a wide variety of applications because of its low cost, and has a wide application range and a great effect when used. In addition, these resins may be a homo resin, a copolymer or a blend resin. Further, various additives such as an antioxidant, an antistatic agent, a crystal nucleating agent, an inorganic particle, a viscosity reducing agent, a heat stabilizer, and a lubricant may be added to these resins.

In the present invention, the thermosetting resin is a resin whose resin is cured by heating. Examples of the thermosetting resin which can be used in carrying out the present invention include epoxy resin, melamine resin, and urea resin. Resins, unsaturated polyester resins, urethane resins and the like are typical resins.

In the present invention, the resin film to be treated may be in the form of a non-oriented film, a uniaxially stretched film, a biaxially oriented film, or the like, but is stretched in the longitudinal and width directions. A biaxially oriented film having biaxially oriented molecules is optimal.

In particular, it is preferable to use the heat retaining wall plate according to the present invention during the manufacturing process of the biaxially oriented film. In particular, in order to form a film having a strong orientation in the longitudinal direction and the width direction, In addition, it can be stretched in multiple stages, or can be further stretched in the longitudinal direction or width direction after biaxial stretching,
The heat retaining wallboard according to the present invention can be used effectively in such a process. Thus, for example, by using the partition plate of the present invention for a partition plate for heating such as a tenter,
Since impurities such as monomers, oligomers, and polymers deposited on the partition plate can be decomposed, the surface of the partition plate is always kept clean, reducing the need to stop production and cleaning the partition plate. This makes it less likely that the film will fall from the surface and give a defect to the film surface, thereby making it possible to form a film with higher productivity.

In the case of the thus obtained film, especially a biaxially stretched film, a film for optical use such as a base film for magnetic recording, which requires no film surface defects, a film for condenser, and a polarizing film. It is particularly effective for uses such as a base film for a thermal transfer ribbon.

Next, an example of a method of using the partition plate of the present invention will be described, but the present invention is not limited thereto.

First, a raw material of a thermoplastic resin is prepared in the form of pellets or the like, and if necessary, pre-drying is performed in hot air or under vacuum, and then supplied to an extruder. In the extruder, the resin heated and melted above the melting point passes through a heated pipe connecting a filter, a gear pump, and the like in a molten state to remove foreign matter. At this time, by connecting the gear pump, the uniformity of the resin extrusion amount is improved, and the effect of reducing the thickness unevenness is high. The molten resin sent from the extruder to the die is formed into a desired shape in the die and then discharged. The resin temperature at the time of this discharge is usually equal to or higher than the melting end temperature (Tme), but after cooling the molten resin to a temperature equal to or lower than the melting end temperature (Tme), the resin is extruded from a die to obtain a film having less thickness unevenness. You can also. That is, the melting is usually at or above the melting end temperature (Tme), but is lower than the melting end temperature (Tme) and exceeds the temperature drop crystallization onset temperature (Tcb).
You may discharge in what is called a supercooled state. In addition, the melting end temperature (Tme) and the cooling crystallization start temperature (Tcb) can be determined by a differential scanning calorimeter (DSC). DS
C is a method generally used in thermal analysis, and is a method of measuring endothermic and exothermic accompanying a state change such as melting, crystallization, phase transition, and thermal decomposition of a substance. The DSC can measure the melting temperature of the thermoplastic resin when the temperature rises and the crystallization temperature when the temperature falls.

The sheet-like molten resin discharged from the die is applied with static electricity, brought into close contact with the drum, and cooled and solidified on a casting drum (roll). This is sufficiently preheated in a preheating roll or an oven composed of a partition plate having a photocatalyst layer, and then stretched with a stretching roll in the longitudinal direction at a temperature higher than the glass transition temperature Tg of the resin, the temperature rise crystallization temperature TCC.
The film is heated to less than 1 and stretched by one or more stages at an arbitrary magnification of about 2 to 10 times, and fixed by a cooling roll.

This uniaxially stretched film is subjected to a tenter oven comprising a partition plate having a photocatalyst layer, stretched 3 to 10 times in the width direction at a temperature of Tg or more, and biaxially stretched. The resin is cooled to a temperature below the glass transition point, preferably to a temperature below the glass transition point of -10 ° C. In order to impart thermal dimensional stability, it is preferable to perform heat treatment at a temperature of the melting point Tm to (Tm-100) ° C. of the resin. If heat treatment is performed at the same temperature immediately after stretching, the softened film in the heat treatment process is drawn into the stretching process due to the stress during stretching and the heat shrinkage stress,
The bowing phenomenon occurs, and the refractive index ellipsoid of the film is distorted, and as a result, a distribution occurs in the physical properties in the width direction.

Therefore, in order to avoid these bowing phenomena, the resin is once cooled to a temperature lower than the glass transition point of the resin after the biaxial stretching, and a hard portion is provided between the stretching step and the heat treatment step, and the respective steps are separated. By performing the heat treatment after this, the bowing phenomenon can be suppressed. Furthermore, it is preferable to perform a relaxation treatment for reducing the size during and after the heat treatment because higher thermal dimensional stability can be obtained. However, it is not preferable to perform a heat treatment at an excessively high heat treatment temperature or a heat treatment at an excessively high relaxation rate in order to pursue thermal dimensional stability because characteristics such as strength and flatness are reduced. The film thus obtained is subjected to a corona discharge treatment or a flame treatment, if necessary, and then gradually cooled to room temperature, and then passed through a transfer roll to be wound into a wound product by a winder. No impurities adhere to the partition plates in these ovens, nor do they fall onto the film and become defects on the film surface.

[0023]

[Method of evaluating physical property values] Thermal characteristics: As a differential scanning calorimeter, a robot DSC “RD” manufactured by Seiko Electronics Industry Co., Ltd.
C220 ”and a disk station“ SSC / 5200 ”made by the company as a data analyzer, and about 10 mg of the sample was placed on an aluminum pan at 300 ° C. for 5 minutes.
The mixture was melted and held for 1 minute, quenched and solidified with liquid nitrogen, and then heated from room temperature at a rate of temperature increase of 20 ° C./minute. The peak temperature of the glass transition point observed at this time was Tg, the start temperature of the melting endothermic peak was Tmb, the peak temperature was Tm, and the peak end temperature was Tme. After 5 mg of the sample was melted and held at 300 ° C. for 5 minutes, the temperature was decreased at a rate of 20 ° C./min. The start temperature of the exothermic peak of cooling crystallization observed at this time was Tcb, the peak temperature was Tc, and the end temperature of the peak was Tce.

2. Intrinsic viscosity [η] of polyester: 25
At ゜ C, the value was determined by the following formula using o-chlorophenol as a solvent.

[Η] = lm [ηsp / c] The specific viscosity ηsp is obtained by subtracting 1 from the relative viscosity ηr. c is the concentration. The unit is expressed in dl / g.

3. Surface maximum roughness Rt: JIS B060
The measurement is performed using a high-precision thin film step meter ET-10 manufactured by Kosaka Laboratory Co., Ltd. according to 1-11976. Stylus tip radius 0.
5 μm, needle pressure 5 mg, measurement length 1 mm, cutoff 0.0
8 mm. In the case of a large specimen such as a metal roll, transfer is measured by the replica method before measurement.

[0027]

The present invention will be described below in more detail with reference to examples and comparative examples.

Example 1 As a thermoplastic resin, polyethylene terephthalate (PET) having an intrinsic viscosity [η] of 0.65 was used. When the thermal characteristics of PET were measured using DSC, Tg: 69 ° C.
Tmb: 240 ° C, Tm: 255 ° C, Tme: 268 ° C, T
cb: 203 ° C., Tc: 188 ° C., Tce: 174 ° C. The PET pellets were vacuum-dried at 180 ° C. for 3 hours and supplied to a tandem extruder to be melted at 285 ° C.
The mixture was cooled to 245 ° C. by a second-stage extruder and supplied to a die in a supercooled state.

As the die, a manifold die having a lip width of 960 mm, a lip gap of 2 mm, and a land length of 55 mm was used.
In this state, the resin is extruded, and the supercooled film extruded from the die is applied with static electricity while the surface temperature is 2
It was drawn at a rate of 60 m / min onto a chromium-plated casting drum maintained at 5 ° C. and having a maximum surface roughness Rt of 0.2 μm and quenched and solidified. The film was supplied to a longitudinal roll stretching machine and stretched 4.5 times at a stretching temperature of 128 ° C. In this case, the longitudinal stretching machine uses a chrome plating roll (Rt 0.6 μm) where the preheating temperature is as low as 80 ° C. and 250 mm when the preheating temperature is as high as 85 to 115 ° C.
mm diameter alumina ceramic roll (maximum surface roughness Rt
0.9 μm). A silicon rubber roll having a thickness of 5 mm was used on one side of the nip roll for stretching, and an alumina ceramic roll having a diameter of 120 mm (surface maximum roughness Rt 0.6 μm) was used on the other side. Subsequently, while holding both ends of the uniaxially stretched film with clips, a partition plate having a photocatalytic layer (alumina oxide was sprayed on the surface of a stainless steel plate at a thickness of 1 μm, and then anatase-type titanium oxide using silicon oxide as a binder). The plate was impregnated with the sol solution and a photocatalyst layer having a thickness of 2 μm was immobilized on the plate base), and was stretched 4.5 times in the width direction in an atmosphere heated to 120 ° C. After cooling, heat treatment at 230 ° C. was performed in a tenter,
After quenching to 0 ° C, gradually cool to room temperature and cool to a thickness of 12 μm
Was obtained. At this time, the heat fixing section of the tenter oven and the cooling zone thereafter were irradiated with ultraviolet rays of about 50 mW / cm ² from an ultraviolet irradiation device.
Cooling water was flowed through the partition plate in the cooling zone after the heat treatment to keep the wall surface temperature at 100 ° C. or less.

Thus, even if the film is formed for a long period of time of not less than 6 months, no deposits are deposited on the partition plate in the oven tenter, and there is no drop of any impurities from the plate, and a stable film is formed. Was possible. Also, the surface of the obtained film was a high-quality film without surface defects such as falling objects such as oligomers.

Comparative Example 1 A biaxially oriented film having a thickness of 12 μm was obtained in the same manner as in Example 1 except that a normal stainless steel plate was used instead of the partition plate having a photocatalyst layer used in Example 1.

Thus, film formation was continued for a long period of six months or more. However, many deposits such as PET monomers, oligomers, thermal decomposition products, and lubricating oil were deposited on the stainless steel plate, and the partition plate was washed every 20 days. Therefore, stable film formation was not possible. Also, the surface of the obtained film had many surface defects such as oil stains and oligomer adhesion, and only a low-quality film was obtained.

Example 2 As the thermoplastic resin, polyethylene terephthalate (PET) having an intrinsic viscosity [η] of 0.65 was used. When the thermal characteristics of PET were measured using DSC, Tg: 69 ° C.
Tmb: 240 ° C, Tm: 255 ° C, Tme: 268 ° C, T
cb: 203 ° C., Tc: 188 ° C., Tce: 174 ° C. The PET pellets were vacuum-dried at 180 ° C. for 3 hours and supplied to a tandem extruder to be melted at 285 ° C.
The mixture was cooled to 245 ° C. by a second-stage extruder and supplied to a die in a supercooled state.

As the die, a manifold die having a lip width of 960 mm, a lip gap of 2 mm and a land length of 55 mm was used.
In this state, the resin is extruded, and the supercooled film extruded from the die is applied with static electricity while the surface temperature is 2
It was drawn at a rate of 60 m / min onto a chromium-plated casting drum maintained at 5 ° C. and having a maximum surface roughness Rt of 0.2 μm and quenched and solidified. The film was supplied to a longitudinal roll stretching machine and stretched 4.5 times at a stretching temperature of 128 ° C. In this case, the longitudinal stretching machine uses a chrome plating roll (Rt 0.6 μm) where the preheating temperature is as low as 80 ° C. and 250 mm when the preheating temperature is as high as 85 to 115 ° C.
mm diameter alumina ceramic roll (maximum surface roughness Rt
0.9 μm). A silicon rubber roll having a thickness of 5 mm was used on one side of the nip roll for stretching, and an alumina ceramic roll having a diameter of 120 mm (surface maximum roughness Rt 0.6 μm) was used on the other side. Subsequently, a sol solution of anatase type titanium oxide using titanium peroxide as a binder is applied to the surface of a partition plate having a photocatalytic layer while holding both ends of the uniaxially stretched film with clips, and baked at 200 ° C. or more. To form a photocatalyst layer having a thickness of 2 μm.)
Stretched 4.5 times in the width direction in an atmosphere heated to 200 ° C., once cooled to 65 ° C., and then 230 ° C. in a tenter.
And then rapidly cooled to 140 ° C., gradually cooled to room temperature, and cooled to obtain a biaxially oriented film having a thickness of 12 μm. At this time, ultraviolet rays from an ultraviolet irradiation device were applied to the heat fixing section of the tenter oven and the cooling zone thereafter.
Irradiation was performed at about 0 mW / cm ² . Further, cooling water is supplied to the partition plate in the cooling zone after the heat treatment to reduce the wall surface temperature to 10%.
It was kept below 0 ° C.

Thus, even if film formation is continued for a long period of time of 6 months or more, no deposits are deposited on the partition plate in the oven tenter, and there is no drop of any impurities from there, and a stable film formation is performed. Was possible. Also, the surface of the obtained film was a high-quality film without surface defects such as falling objects such as oligomers.

[0036]

As described above, according to the heat retaining wall plate of the present invention, there is little need to periodically clean the partition plate.
Not only can a production method excellent in productivity be provided, but also a film having excellent thickness uniformity without surface defects in film properties after biaxial stretching can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 7:00 F term (Reference) 4F100 AA21B AB04 AT00A BA02 BA26 CA30B EJ54 GB90 JJ02 JJ02A JJ10 JL06 YY00 4F203 AA24 AG01 DA08 DB02 DC08 DK02 DL03 4F210 AA24 AG01 QA02 QA03 QC05 QD34 QD35 QD36 QG01

Claims (8)

[Claims] 1. A wall panel for heat insulation, comprising a photocatalyst layer on a surface layer. 2. The wall panel according to claim 1, wherein the photocatalyst layer is made of titanium oxide. 3. The wall plate according to claim 2, wherein the crystal system of titanium oxide is an anatase type. 4. The heat retaining wall plate according to claim 1, which is used at least during heating. 5. The wall panel according to claim 1, wherein the surface temperature of the photocatalyst layer is maintained at 150 ° C. or lower. 6. The method according to claim 1, wherein the surface layer of the photocatalyst layer is used while being irradiated with ultraviolet rays of 400 nm or less.
The wall plate for heat retention according to any one of claims 1 to 5. 7. A film heat treatment apparatus, wherein the heat retaining wall plate according to claim 1, 2, 3, 4, 5, or 6 is used as heating means for a film to be processed. 8. A method for producing and processing a film, wherein the heat-treating wall plate according to claim 1, 2, 3, 4, 5, or 6 is used as a heating means for a film to be processed.