JP4077744B2 - Method for producing polybutylene terephthalate film, apparatus for producing the same, and polybutylene terephthalate film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polybutylene terephthalate film, which is a thin film and excellent in film thickness uniformity and thermal shrinkage, a production apparatus therefor, and the polybutylene terephthalate film.
[0002]
[Prior art]
Polybutylene terephthalate (PBT) resin, which has excellent mechanical strength, heat resistance, chemical resistance, impact resistance, electrical properties, etc., has been attracting attention as a plastic for engineering. Injection of automotive parts, electrical / electronic parts, etc. Its application has been promoted mainly in the molding field. However, polybutylene terephthalate resin has (a) a high crystallization rate, for example, if it is stretched in the machine direction after crystallization, then it cannot be stretched in the transverse direction. (B) rapid stretching due to low melt tension. (C) Since the glass transition temperature is close to room temperature, film defects are likely to occur. Thus, polybutylene terephthalate resin is extremely difficult to form into a film, and there are few examples of use as a film. In general, a film thickness required for using a resin film as a packaging material is about 10 to 30 μm. Therefore, in order to use a film made of polybutylene terephthalate resin as a packaging material, it is indispensable to reduce the thickness.
[0003]
Generally, there are two methods for producing resin films: the T-die method and the inflation molding method. Compared to the T-die method, the inflation molding method is more productive and economical, and the production of thin films is possible. Suitable for However, the polybutylene terephthalate film produced by the inflation molding method has a problem that the film thickness unevenness is large and the thermal contraction rate is large.
[0004]
In contrast, a polybutylene terephthalate resin having an intrinsic viscosity of 1.0 or more has an extrusion resin temperature of the following formula:
Melting point (° C.) <Extruded resin temperature (° C.) <Melting point−26 + 53 × Intrinsic viscosity (° C.)
A method of forming a film by an inflation molding method so as to satisfy the above has been proposed (Patent Document 1).
[0005]
On the other hand, when a polybutylene terephthalate film is produced by the T-die method, the unstretched film is generally biaxially stretched in order to improve the physical properties of the resulting unstretched film and reduce the film thickness. As a method for producing such a biaxially stretched film of PBT, Patent Document 2 discloses a method of simultaneously biaxially stretching an unstretched film in the vertical and horizontal directions at a predetermined temperature, and Patent Document 3 and Patent Document 4 include a predetermined method. A method of successively biaxially stretching an unstretched film at a temperature and a speed of 2 is proposed.
[0006]
[Patent Document 1]
Japanese Patent Publication No. 7-33048
[Patent Document 2]
JP-A-49-80178
[Patent Document 3]
Japanese Patent Publication No.51-40904
[Patent Document 4]
JP 51-146572 A
[0007]
[Problems to be solved by the invention]
However, the method described in Patent Document 1 has a problem of insufficient productivity. In addition, the methods of Patent Documents 2 to 4 are biaxially stretched for an unstretched film prepared by quenching a molten polybutylene terephthalate resin, and therefore the workability is poor and the heat shrinkage rate is insufficiently improved. there were. Therefore, there has been a problem that it is easily contracted during the secondary processing. In order to improve the film-forming properties of PBT during biaxial stretching, methods such as laminating and extruding with other resin films, and adding compatible resins such as polyethylene and polypropylene have been proposed. It was difficult to reduce the film thickness to a film thickness of about 10 to 30 μm, which is optimal as a film.
[0008]
Accordingly, an object of the present invention is to provide a method and apparatus for producing a polybutylene terephthalate film, which is a thin film and excellent in film thickness uniformity and thermal shrinkage, and a polybutylene terephthalate film.
[0009]
[Means for Solving the Problems]
As a result of diligent research in view of the above object, the present inventor, in a method for producing a polybutylene terephthalate film in which a polybutylene terephthalate resin is formed into a film by an air-cooled inflation molding method, expands bubbles while maintaining the amorphous state. The present inventors have found that a polybutylene terephthalate film having excellent film thickness uniformity and thermal shrinkage can be manufactured while being a thin film. The inventor of the present invention also provides a method for producing a polybutylene terephthalate film in which a polybutylene terephthalate resin is formed into a film by a stretching method. It was discovered that a polybutylene terephthalate film excellent in film thickness uniformity and thermal shrinkage can be produced while being a thin film by simultaneously forming biaxial stretching while maintaining the film in an amorphous state. The present invention has been completed based on this invention.
[0010]
That is, in the first method for producing a polybutylene terephthalate film of the present invention, a bubble is formed by injecting air into a molten polybutylene terephthalate resin extruded in a tube shape from an annular die, and the bubble is expanded by an internal pressure. And forming a tubular film by air cooling, and a method for producing a polybutylene terephthalate film including an air-cooled inflation molding process in which the obtained tubular film is folded into a sheet while being pulled by a pair of nip rolls, (1) By blowing hot air from a first hot air blowing device provided in the vicinity of the annular die, the neck of the bubble is cooled to 180 ° C. to 195 ° C., and (2) the first Hot air is jetted from the second hot air blowing device installed at the top of the hot air blowing device The bubble is further cooled to 150 ° C. or higher and 180 ° C. or lower, so that the bubble is expanded while being held in an amorphous state, and (3) provided at the upper part of the second hot air blowing device. By blowing hot air from the third hot air blowing device, the bubble frost line is cooled to 90 ° C. or higher and 130 ° C. or lower, and (4) the upper bubble region above the frost line is removed. Surrounding the upper bubble region by a partition wall for blocking warm air from the external atmosphere and blowing out hot air from each of the first to third hot air blowing devices along the outer surface of the upper bubble region, A heating means is provided on the inner surface side of the partition wall, so that the upper bubble region is maintained between the glass transition temperature of the polybutylene terephthalate resin and the glass transition temperature of + 65 ° C. or less.
[0011]
In the first production method, the blow-up ratio is preferably 2.0 to 4.5. As a result, the bubbles can be stretched in a balanced manner in the machine direction and the transverse direction at the same time. The upper bubble region is preferably surrounded by a cylindrical fiber, which can prevent the bubble from rolling. It is preferable that the temperature of the warm air to be ejected from the first and second warm air blowing devices is 25 to 50 ° C. The temperature of the warm air blown from the third warm air blowing device is preferably higher than the glass transition temperature of the polybutylene terephthalate resin to not more than the glass transition temperature + 65 ° C.
[0012]
In the first production method, the polybutylene terephthalate resin is further uniaxially cold-stretched twice or more in the machine direction or the transverse direction at a temperature above the glass transition temperature of the polybutylene terephthalate resin to the glass transition temperature + 60 ° C. It is preferable to perform biaxial cold stretching successively at a surface magnification of 2 times or more in the transverse direction. Thereby, the uniformity of the film thickness and the heat shrinkage rate are further improved. When such uniaxial cold stretching or sequential biaxial cold stretching is also performed, it is preferable that (1) the tubular film is formed, and (2) the uniaxial cold stretching or the sequential biaxial cold stretching is continuously performed by an in-line method. .
[0013]
In the first production method, when the uniaxial cold stretching is performed by a roll method, or when the sequential biaxial cold stretching is performed by a roll method and a tenter method, before the uniaxial cold stretching or the sequential biaxial cold stretching. In addition, it is preferable to divide the sheet-like tubular film taken up by the nip roll into two in advance. In this case, it is preferable that (1) the tube-shaped film is formed, (2) the tube-shaped film is divided into two parts, and (3) the uniaxial cold stretching or the sequential biaxial cold stretching is continuously performed by an inline method. .
[0014]
The film subjected to cold drawing in the first production method has no tearability in any direction, and the heat shrinkage ratio in the direction cold drawn by the uniaxial cold drawing or the sequential biaxial cold drawing is 1%. It is as follows. The film subjected to cold drawing in the first production method has innumerable fine linear wrinkles extending in the machine direction or the transverse direction. The height difference of the concavo-convex structure formed by such linear wrinkles is 50 to 500 nm, and the width of the concavo-convex structure is 500 to 20000 nm.
[0015]
The second method for producing a polybutylene terephthalate film of the present invention is a method for producing a polybutylene terephthalate film in which a polybutylene terephthalate resin is formed into a film by a stretching method. The molten polybutylene terephthalate resin is extruded from a die and heated casting rolls. An amorphous sheet is formed by removing the temperature from 180 ° C. to 195 ° C., and the resulting amorphous sheet is biaxially maintained while maintaining an amorphous state at 150 ° C. to 180 ° C. The film is stretched and then rapidly cooled.
[0016]
The apparatus for producing a polybutylene terephthalate film of the present invention comprises: (a) an extruder for heating and melting the polybutylene terephthalate resin and sending it; and (b) a molten polybutylene terephthalate connected to the downstream end of the extruder. An annular die for extruding the resin into a tube, and (c) an air injection means for injecting air into the molten polybutylene terephthalate resin extruded from the annular die into the tube, and (d) Production of a polybutylene terephthalate film comprising at least an inflation molding device having air cooling means for air-cooling the bubbles, and (e) a pair of nip rolls for taking up a tubular film obtained by air-cooling the bubbles. The apparatus, wherein the air cooling means is (1) provided in the vicinity of the annular die, A first hot air blowing device for cooling the neck of the bubble, and (2) provided above the first hot air blowing device, so that the bubble expands in an amorphous state. A second hot air blowing device for further cooling the bubble; and (3) a third hot air for cooling the bubble frost line provided at the upper part of the second hot air blowing device. A blowing device, and (4) provided above the third warm air blowing device and around the upper bubble region above the frost line, shuts off the upper bubble region from the external atmosphere, and A partition for blowing warm air blown from each of the third warm air blowing devices along the outer surface of the upper bubble region, and (5) a heating means provided on the inner surface side of the partition, 6) The upper bubble area on the inner surface side of the partition wall It is provided so as to surround the vicinity of the region, and has a cylindrical fiber for preventing the bubble from rolling.
[0017]
In the production apparatus of the present invention, it is preferable that the apparatus further includes cold drawing means for cold drawing in the machine direction and / or the transverse direction, and the inflation molding section and the cold drawing means are in-line configuration. The manufacturing apparatus having the cold drawing means includes: (1) an edge position control device for controlling the edge position of the sheet-like tubular film taken up by the nip roll to be constant, and (2) the edge edge. A cutting means for dividing the tubular film whose position is controlled to be constant, and further comprising: the inflation molding section; the edge position control device; the cutting means; and the cold drawing means. Is preferably an in-line configuration. A cutter is preferable as the cutting means.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[1] Method for producing polybutylene terephthalate film
(1) Air-cooled inflation molding method
FIG. 1 is a schematic side view showing the steps of a method for producing a polybutylene terephthalate film by the air-cooled inflation molding method of the present invention. The tube-like film extruded from the annular die 1 attached to the extruder 12 is supplied with air from the air injection pipe 26 to rapidly expand into a film having a predetermined width, and is sandwiched between nip rolls 13 of the take-up machine. And is taken up by the take-up reel 14. There is no particular limitation on the air injection means for supplying air for injecting into the tubular film, such as a means configured to connect the air injection pipe 26 to the blower, a means configured to connect the air injection pipe 26 to the compressed air cylinder, etc. Can be mentioned.
[0019]
The polybutylene terephthalate resin used as a raw material is not particularly limited, but is preferably composed of a homopolymer having 1,4-butanediol and terephthalic acid as constituent components. However, a diol component other than 1,4-butanediol or a cambonic acid component other than terephthalic acid may be included as a copolymer component as long as physical properties such as shape memory ability and heat shrinkability are not impaired. Examples of such a diol component include ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-cyclohexane methanol, and the like. Examples of the dicarboxylic acid component include isophthalic acid, sebacic acid, adipic acid, azelaic acid, and succinic acid. Specific examples of preferable polybutylene terephthalate resins include homopolybutylene terephthalate resins commercially available from Toray Industries, Inc. under the trade name “Trecon”.
[0020]
Polybutylene terephthalate resin is a known additive added to general thermoplastic resins and thermosetting resins, that is, stabilizers such as plasticizers, antioxidants and ultraviolet absorbers, antistatic agents, surfactants, Colorants such as dyes and pigments, lubricants for improving fluidity, crystallization accelerators (nucleating agents), inorganic fillers, and the like can be appropriately used according to the required performance. In addition, a small amount of other thermoplastic resin can be supplementarily used depending on the purpose within a range not impairing the effects of the present invention.
[0021]
In order to produce a polybutylene terephthalate film, first, kneading of a polybutylene terephthalate resin and a desired additive is performed at a resin temperature of 230 to 260 ° C. If the kneading temperature is higher than 260 ° C, the resin may be thermally deteriorated. For this reason, when kneading is performed in an extruder such as a twin screw extruder, one having a screw structure that does not generate heat or one having an appropriate cooling device is used. It is not preferable that the lower limit of the kneading temperature is less than 230 ° C. because the amount of extrusion becomes unstable.
[0022]
The resin temperature extruded from the inflation annular die 1 is preferably 210 to 250 ° C, and more preferably 220 to 230 ° C. The resin pressure extruded from the inflation annular die 1 is 100 to 120 kg / cm.²And The diameter of the inflation annular die 1 is preferably 150 to 300 mm.
[0023]
The bubble 3 pushed out from the annular die 1 is stretched not only in MD (machine direction) but also in TD (lateral direction) while being cooled by a cooling device. This is shown schematically in FIG. 2, which is an embodiment of the present invention.
[0024]
In FIG. 2, the bubble cooling device includes a first hot air blowing device 20 provided in the vicinity of the annular die 1 and a second hot air blowing device 21 provided on the upper portion of the first hot air blowing device 20. A third hot air blowing device 22 provided above the second hot air blowing device 21, a partition wall 23 provided above the third warm air blowing device 22, and an inner surface side of the partition wall 23 It has a heating means 24 provided and a cylindrical fiber 25 provided inside the partition wall 23 (on the bubble 3 side). In FIG. 2, reference numeral 15 denotes a heat insulating material provided on the upper portion of the annular die 1, and 16 denotes a guide roll.
[0025]
In the apparatus having the above configuration, the arrangement of the hot air blowing apparatuses 20 to 22 and the partition wall 23 is determined by the temperature control of the bubble 3 formed by the air-cooled inflation molding method. Therefore, the shape and temperature distribution of the bubble 3 will be described below. To do.
[0026]
The melted polybutylene terephthalate resin or polybutylene terephthalate resin composition is extruded from the annular orifice 11 of the die 1 to form a bubble 3. The bubble 3 immediately after being extruded has a small diameter due to its low melt tension. A so-called neck portion 31 is formed. In the neck portion 31, the bubble 3 is mainly stretched to MD. Next, the bubble 3 rapidly expands to a predetermined bubble diameter. In the inflating portion 32, the bubble 3 is stretched simultaneously in the MD and TD. There is a frost line 34 in the vicinity of the upper part of the inflating part 32, where the polybutylene terephthalate resin (composition) is cooled and solidified. The bubble 3 is further cooled by the partition wall 23 and the heating means 24 provided in the bubble region 33 above the frost line 34.
[0027]
In order to obtain a polybutylene terephthalate film by the air-cooled inflation molding method as in the present invention, the temperature of each part of the bubble 3 is controlled as follows.
(a) The temperature immediately after extrusion from the annular die 1 is 210 to 250 ° C.
(b) The neck portion 31 is cooled to 180 ° C. or higher and 195 ° C. or lower.
(c) The expansion part 32 is cooled to 150 ° C. to 180 ° C.
(d) The frost line 34 is cooled to 90 ° C. to 130 ° C.
(e) In the upper bubble region 33, the glass transition temperature of the polybutylene terephthalate resin is maintained above the glass transition temperature to below the glass transition temperature + 65 ° C.
[0028]
The condition (a) is the same as described above, but the condition (b) is that the neck part 31 is not cooled to 180 ° C. or more and 195 ° C. or less, and the next expansion part 32 converts it to MD and TD. Simultaneous biaxial stretching cannot be achieved sufficiently. That is, by removing the temperature from 180 ° C. to 195 ° C. at the neck portion 31, the expanded portion 32 can be cooled / held at 150 ° C. to 180 ° C. (condition (c)). If the expanded portion 32 is not maintained at 150 ° C. or higher and 180 ° C. or lower, the expanded portion 32 does not have an appropriate melt tension, and the MD is mainly stretched, so that it cannot be thinned. If the expanded portion 32 is set to less than 150 ° C., crystallization proceeds, so that the amorphous state cannot be maintained.
[0029]
In order to satisfy such temperature conditions, the blow-up ratio is preferably set to 2.0 to 4.5. In particular, the blow-up ratio is desirably 2.0 to 2.8.
[0030]
Regarding condition (d), simultaneous biaxial stretching of the bubble 3 to MD and TD can be sufficiently achieved by removing the bubble temperature in the frost line 34 from 90 ° C. to 130 ° C. If the bubble temperature in the frost line 34 is lower than 90 ° C., film wrinkles may occur.
[0031]
Regarding the condition (e), by maintaining the bubble 3 above the glass transition temperature of the polybutylene terephthalate resin to the glass transition temperature + 65 ° C. or lower above the frost line 34, the generation of film defects can be prevented and the film is uniformly thin Formation of the bubble 3 can be stabilized. Preferably, the upper bubble region 33 is maintained at 90-110 ° C. If the temperature of the upper bubble region 33 is kept below the glass transition temperature without providing the partition wall 23 and the heating means 24, non-uniform stretching may occur, so that the bubble 3 as a whole becomes unstable. The glass transition temperature of the polybutylene terephthalate resin is generally 22 to 45 ° C. In this specification, the glass transition temperature is measured according to JIS K7121.
[0032]
In the present invention, it is preferable to further surround the outer periphery of the upper bubble region 33 with a cylindrical fiber 25 as shown in FIG. As a result, the temperature of the upper bubble region 33 can be further stabilized, and the roll of the bubble 3 can be prevented.
[0033]
In order to control the temperature of the bubble 3 as described above, the first hot air blowing device 20, the second hot air blowing device 21, the third hot air blowing device 22, the partition wall 23, the heating means 24, and the cylinder The arrangement of the fibers 25 is as follows.
(B) First hot air blowing device 20
It is provided in the immediate vicinity of the annular die 1, and hot air is jetted so that the temperature of the neck portion 31 is cooled to 180 ° C. to 195 ° C. The temperature of the hot air is preferably 25 to 50 ° C.
(B) Second hot air blowing device 21
It is provided immediately below the expansion section 32, and hot air is jetted so that the temperature of the expansion section 32 is removed from 150 ° C to 180 ° C. The temperature of the hot air is preferably 25 to 50 ° C.
(C) Third warm air blowing device 22
It is provided immediately below the frost line 34, and hot air is blown out so that the temperature of the frost line 34 is removed from 90 ° C to 130 ° C. The temperature of the warm air is preferably from the glass transition temperature of the polybutylene terephthalate resin to the glass transition temperature + 65 ° C. or less.
(D) Bulkhead 23 and heating means 24
The partition wall 23 is located above the third hot air blowing device 22 and surrounds the upper bubble region 33, and the hot air blown from each of the first to third hot air blowing devices is the outer surface of the upper bubble region 33. It is provided to blow up along. The heating means 24 is provided on the inner surface side of the partition wall 23. By providing the partition wall 23 and the heating means 24, the upper bubble region 33 is shielded from the influence of the external atmosphere (temperature, temperature, etc.), and is always kept above the glass transition temperature of the polybutylene terephthalate resin to below the glass transition temperature + 65 ° C. be able to.
(E) Cylindrical fiber 25
An upper bubble region 33 is provided inside the partition wall 23 so as to surround it.
[0034]
In the above method, there is no particular limitation on the means for supplying the warm air to be ejected from each of the first to third warm air blowing devices, and examples include a blower capable of controlling the temperature. The flow rate of the warm air blown from each of the first to third warm air blowing devices is appropriately adjusted so that the bubble temperatures at the neck portion 31, the expansion portion 32, and the frost line 34 are within the above temperature ranges, respectively. . Since the bubble 3 becomes unstable unless a stable cooling effect is obtained, the temperature of the hot air is controlled so as not to change as much as possible.
[0035]
The material of the partition wall 23 is not particularly limited, but is preferably an acrylic resin so that the upper bubble region 33 surrounded by the partition wall 23 can be observed. There is no restriction | limiting in particular in the shape of the partition 23, For example, the side was comprised from the four wall surfaces so that the upper bubble area | region 33 can be enclosed from four directions is mentioned. As the heating means 24 provided inside the partition wall 23, for example, a rod-shaped or ribbon-shaped electric heater can be used. An aluminum foil may be attached to the inner surface of the partition wall 23 to block heat radiation.
[0036]
As the fiber constituting the cylindrical fiber 25, natural fibers such as silk and cotton, plastic fibers such as nylon, polypropylene and polyester, metal fibers such as stainless steel, copper, brass and nickel can be used. When a net-like fiber is used as the cylindrical fiber 25, the mesh is preferably 5 to 20 mesh, particularly 8 to 10 mesh.
[0037]
Film formation of the polybutylene terephthalate resin by the air-cooled inflation molding method in the present invention is possible by maintaining the above requirements, and general conditions of the inflation method can be applied to other conditions. That is, using a crosshead die, the tube-shaped molten polybutylene terephthalate resin is extruded upward or downward, the end is sandwiched between pinch rolls, air is fed into the inside, and the die is continuously wound while being inflated to a predetermined size. It is also possible to prevent uneven thickness by rotating or reversing.
[0038]
According to the manufacturing method of the present invention, each part of the bubble (immediately after extrusion, the neck part, the expansion part, the frost line, and the upper bubble area) is always maintained at a desired temperature, so that the quality is always uniform. Furthermore, high-speed film formation is possible.
[0039]
The polybutylene terephthalate film (inflated PBT film) obtained by the above-described air-cooled inflation molding is further uniaxially cooled in the machine direction or the transverse direction at a temperature above the glass transition temperature of the polybutylene terephthalate resin to a glass transition temperature + 60 ° C. or less. It is preferable to draw, or sequentially biaxially cold-draw in the machine direction and the transverse direction. As a result, the inflation PBT film can be further thinned, and the film thickness uniformity and transparency can be improved. A preferred cold stretching temperature is 55 to 65 ° C. The stretching ratio of the uniaxial cold stretching is preferably 2 times or more in the machine direction or the transverse direction, and more preferably 2 to 6 times. When uniaxial cold drawing is performed, it is preferably performed in the machine direction. The stretching ratio of the sequential biaxial cold stretching is preferably 4 times or more in terms of surface magnification, and more preferably 4 to 16 times.
[0040]
In general, when a polybutylene terephthalate film is stretched at a glass transition temperature + 60 ° C. or higher, crystals are oriented in the stretching direction, so that the tensile strength, elastic modulus, rigidity, etc. in the orientation direction are greatly improved. However, since the strength in the non-oriented direction is lowered, there is a problem that the film is torn when sequentially biaxially stretched at a temperature higher than the glass transition temperature + 60 ° C. In contrast, when a polybutylene terephthalate film is cold-stretched at a temperature above the glass transition temperature of the polybutylene terephthalate resin to a glass transition temperature + 60 ° C. or less, it is stretched compared to when it is stretched at a temperature above the glass transition temperature + 60 ° C. The orientation of molecular chains in the direction is small. For this reason, even if it carries out sequential biaxial stretching with respect to an inflation PBT film at the temperature more than glass transition temperature-glass transition temperature +60 degrees C or less, a film does not tear. Moreover, even when uniaxial stretching is performed by cold stretching at a temperature higher than the glass transition temperature to a glass transition temperature + 60 ° C. or less, easy tearing does not occur. Further, by cold drawing at a temperature higher than the glass transition temperature to a glass transition temperature + 60 ° C. or less, the crystals are broken and fine spherulites are generated, so that the transparency of the film is improved.
[0041]
Since the polybutylene terephthalate film obtained by air-cooled inflation molding is in a tube shape, the tube-shaped polybutylene terephthalate is used when uniaxial cold stretching is performed by a roll method, or when sequential biaxial cold stretching is performed by a roll method and a tenter method. The film is cut into two and then cold drawn. To cut the tube-like inflation PBT film into two, in the state of the folded sheet, tear it with a cutter horizontally from the folds at both ends against the sheet surface, or with slitters at both ends in the lateral direction Cut off.
[0042]
(1) Air-cooled inflation molding, (2) Cutting of tubular inflation PBT film, and (3) Cold drawing process, after air-cooled inflation molding, each of the blown PBT films cut into two is once wound into separate wound films. Further, it may be a sequential process of performing cold stretching while sequentially rewinding each wound film, but is preferably an in-line process in which the processes (1) to (3) are continuously performed on a series of lines.
[0043]
FIGS. 3 (a) and 3 (b) show that a polybutylene terephthalate film obtained by air-cooled inflation molding is cut into two pieces in advance to make a wound film and then biaxially cold-drawn sequentially in the machine direction and the transverse direction. It is the schematic side view ((a)) and schematic plan view ((b)) which show the example of this apparatus.
[0044]
The unwound inflation PBT film 2 is stretched in the machine direction by the slow driving roll 41 and the heating roll 43 between the fast driving roll 42 in the machine direction stretching section 4. The PBT film 2 stretched in the machine direction enters the tenter 5 (laterally stretched portion), is heated while being held at both ends of the film, is stretched in the lateral direction, and is heat-treated. The PBT film 2 stretched also in the transverse direction is rapidly cooled by blowing cooling air in the cooling tower 27.
[0045]
For stretching in the machine direction, as shown in detail in FIG. 4 (a), a large number of rotatable heating rolls 43 are arranged between the foremost slow drive roll 41 and the rearmost fast drive roll 42, This is achieved by passing the inflation PBT film 2 between them and appropriately setting the peripheral speed ratio between the slow drive roll 41 and the fast drive roll 42. The temperature of the heating roll 43 is set so that the temperature of the inflation PBT film is a temperature above the glass transition temperature to a glass transition temperature + 60 ° C. or less.
[0046]
FIGS. 4B and 4C are schematic side views showing another example of the machine direction extending portion 4. FIG. 4B shows an example of a nip roll type, and FIG. 4C shows an example of a clover roll type. In any method, the inflation PBT film 2 is preheated with a plurality of preheating rolls 43, and then heated and stretched between the heated slow driving roll 41 and the fast driving roll 42, and then with a plurality of cooling rolls 44. Cooling.
[0047]
In the tenter 5, a chain (not shown) provided with a film clip roller 51 circulates endlessly along a rail (not shown). The tenter 5 is composed of three parts: a preheating part, a stretching part, and a heat treatment part. The PBT film 2 stretched in the machine direction is heated by blowing hot air introduced from the hot air introduction hole 53 in each of the preheating portion, the stretching portion, and the heat treatment portion. In FIG. 3, reference numeral 52 denotes a gear, and reference numeral 54 denotes a hood for blowing hot air uniformly onto the PBT film 2. The temperature of the hot air blown out in the preheating part, the stretching part and the heat treatment part is set so that the temperature of the PBT film 2 passing through each part is maintained at a temperature higher than the glass transition temperature and not higher than the glass transition temperature + 60 ° C., respectively. The rapid cooling by the cooling tower 27 causes the stretched PBT film 2 to have a temperature not higher than the glass transition temperature.
[0048]
In the case where the inflation PBT film 2 is only uniaxially cold-drawn in the machine direction or the transverse direction, the inflation PBT film 2 may be drawn only by the machine-direction stretched portion 4 or the transverse-direction stretched portion 5 described above and then rapidly cooled.
[0049]
The uniaxial cold drawing in the machine direction or the transverse direction and the sequential biaxial cold drawing in the machine direction and the transverse direction are not limited to the roll method and the tenter method as shown in FIG. Can also be adopted. When the tubular method is employed, the step consisting of (1) air-cooled inflation molding and (2) cold drawing is preferably an in-line step continuously performed on a series of lines.
[0050]
FIG. 5 is a schematic side view showing an example of an in-line apparatus for continuously performing air-cooled inflation molding, cutting of a tubular inflation PBT film, and cold drawing on a series of lines. The tube-shaped film 2 sandwiched between the nip rolls 13 of the take-up machine is folded in the state of a folded sheet by the cutter 18 horizontally from the folded portion at both ends with respect to the sheet surface, and each of the inflation films divided into upper and lower parts. The PBT films 2 ′ and 2 ′ are cold-drawn at the machine direction drawing portions 4 and 4, respectively. As shown in FIG. 5, an edge position control unit (EPC) 8 is preferably provided in front of the cutter 18. As a result, when cutting with the cutter 18, the ear end position (edge position) of the inflation PBT film can always be controlled to a fixed position, so that the tubular inflation PBT film 2 can always be uniformly divided. it can. The edge / position control device 8 shown in FIG. 5 has two guide rolls 81, 81, a connecting shaft 82 that connects the guide rolls 81, 81, and a sensor 83. The inclination of 81 and 81 changes, and the ear end position (edge position) of the inflation PBT film 2 can be always controlled to be constant. The edge position control device is not limited to the one shown in the figure, and other known control mechanisms can be used.
[0051]
In the machine direction stretching sections 4, 4, the inflation PBT films 2 ′, 2 ′ are cold-stretched between the heated slow drive rolls 45, 45 and the cooled fast drive rolls 46, 46. The temperature of the slow drive rolls 45, 45 is set so that the temperature of the inflation PBT film is a temperature above the glass transition temperature to a glass transition temperature + 60 ° C. or less. The temperature of the fast drive rolls 46, 46 is set to a temperature not higher than the glass transition temperature of the inflation PBT film, preferably lower than the glass transition temperature. The stretching ratio may be adjusted by appropriately setting the peripheral speed ratio between the slow drive rolls 45, 45 and the fast drive rolls 46, 46. It is good also as a structure which can provide the tenter 5 (transverse direction extending | stretching part) shown in FIG. 3 after the machine direction extending | stretching parts 4 and 4 and can perform cold extending | stretching to a horizontal direction further.
[0052]
As shown in FIG. 5, it is preferable to provide a heater 19 and heat-treat the film after cold drawing. Instead of the heater 19, heat treatment by roll heating may be used. The heat treatment is preferably performed at a temperature higher than the glass transition temperature of the polybutylene terephthalate film to a melting point of −50 ° C. or lower. Therefore, the temperature of the heater 19 is set so that the temperature of each PBT film 2 ′ after cold drawing is maintained at a temperature above the glass transition temperature and below the glass transition temperature −50 ° C. The heat treatment after cold drawing further improves the transparency, tensile strength, thermal shrinkage rate and film thickness uniformity, and suppresses the generation of wrinkles. By performing the heat treatment at a glass transition temperature of + 60 ° C. or higher and a melting point of −50 ° C. or lower, linear easy tearability can be imparted to the film. When it is not desired to impart linear tearability to the film, the heat treatment may be performed at a temperature higher than the glass transition temperature to less than the glass transition temperature + 60 ° C. By changing the heat treatment temperature in this way, the linear tearability of the film and the accompanying tear strength can be changed.
[0053]
By using the in-line apparatus shown in FIG. 5, a series of steps consisting of (1) air-cooled inflation molding, (2) cutting of tubular inflation PBT film and (3) cold drawing can be made efficient. In FIG. 5, reference numeral 17 denotes a nip roll.
[0054]
(2) Simultaneous biaxial stretching method
FIG. 6 is a schematic plan view showing a process for producing a polybutylene terephthalate film by the simultaneous biaxial stretching method of the present invention. The molten resin extruded from a sheet die (T die) 60 attached to the extruder 12 is taken up by a heating casting roll 61 and is cooled to form an amorphous sheet 6. The obtained amorphous sheet 6 is stretched by a simultaneous biaxial stretching device 7 provided subsequent to the heating casting roll 61, and then rapidly cooled to form a stretched film.
[0055]
The requirements regarding the polybutylene terephthalate resin, the desired additives, and their kneading are the same as in the case of the air-cooled inflation molding described in the above (1), and thus the description thereof is omitted.
[0056]
The molten resin melt-kneaded in the extruder 12 is extruded from the sheet die 60. The extrusion may be performed not only directly from the extruder 12, but also through another extruder, or may be once cooled and pelletized and then passed through the extruder 12 again. The gap of the sheet die 60 is normally 5 mm or less. The resin temperature extruded from the sheet die 60 is preferably 210 to 250 ° C, and more preferably 220 to 230 ° C.
[0057]
The amorphous resin 6 is formed by taking out the molten resin extruded from the sheet die 60 in this way with the heating casting roll 61 and cooling it to 180 ° C. or more and 195 ° C. or less. By forming the amorphous sheet 6 maintained at 180 ° C. or more and 195 ° C. or less, the workability with respect to the subsequent simultaneous biaxial stretching is improved, so that high stretching and thinning are facilitated. Before contacting the heating casting roll 61, the distance between the sheet die 60 and the heating casting roll 61 is preferably 20 cm or less so that the temperature of the extruded molten resin does not drop below 200 ° C. The heating casting roll 61 adjusts the temperature so that the temperature of the amorphous sheet 6 is 180 ° C. or higher and 195 ° C. or lower. When the temperature of the heating casting roll 61 is higher than 200 ° C., the melt tension becomes low, and it becomes difficult to form the amorphous sheet 6.
[0058]
The thickness of the amorphous sheet 6 is preferably 50 to 100 μm. This facilitates thinning by a subsequent stretching process. The thickness of the amorphous sheet 6 is set to 50 to 100 μm, and the neck-in phenomenon (a phenomenon in which the cast sheet extruded from the die becomes narrower than the effective width of the die) when forming the amorphous sheet 6 is suppressed as much as possible. For this purpose, the peripheral speed of the heating casting roll 61 is set to 5 to 15 m / min. The outer diameter of the heating casting roll 61 is preferably 35 to 70 cm.
[0059]
Next, as shown in FIG. 6, the obtained amorphous sheet 6 is simultaneously biaxially stretched while being maintained at 150 ° C. to 180 ° C. in an amorphous state. If the amorphous sheet 6 is not maintained at 150 ° C. or higher and 180 ° C. or lower during simultaneous biaxial stretching, it does not have an appropriate melt tension and cannot be thinned. If the amorphous sheet 6 is set to less than 150 ° C., crystallization proceeds, so that the amorphous state cannot be maintained. There is no particular limitation on the method for holding the amorphous sheet 6 in an amorphous state at 150 ° C. or higher and 180 ° C. or lower, and examples thereof include a method of blowing hot air or using an electric heater. In the case of blowing hot air, it is preferable to blow hot air from both sides of the amorphous sheet 6 through a hood similar to the hood 54 provided in the tenter 5 shown in FIG. When an electric heater is provided, it is preferably provided on both sides of the amorphous sheet 6.
[0060]
In the simultaneous biaxial stretching, in the simultaneous biaxial stretching apparatus 7, the amorphous sheet 6 is stretched in the machine direction between a slow drive rubber roll 74 and a fast drive rubber roll 75 having different peripheral speeds, and a rail (not shown). ) Along the film 73 by a film clip roller 71 provided on a chain 73 circulating endlessly. Although a draw ratio changes with thickness of the amorphous sheet 6, it is preferable to set it as 2 times or more in a machine direction and a horizontal direction, and it is more preferable to set it as 2-4 times in a machine direction and a horizontal direction. The stretching ratio in the machine direction is adjusted by appropriately setting the peripheral speed ratio between the slow drive rubber roll 74 and the fast drive rubber roll 75. The stretching ratio in the transverse direction is adjusted by the angle indicated by α in FIG. In FIG. 6, reference numeral 72 denotes a gear.
[0061]
The stretched film 63 after simultaneous biaxial stretching is rapidly cooled by the cooling air blown by the cooling tower 27 so that the stretched film 63 has a temperature equal to or lower than the glass transition temperature. As a means for rapidly cooling the stretched film 63 after simultaneous biaxial stretching, a method of bringing it into contact with a cooling roll may be employed (not shown).
[0062]
[2] polybutylene terephthalate film
(1) Inflation film
The polybutylene terephthalate film produced by the air-cooled inflation molding method described in the above [1] (1) has excellent film thickness uniformity and a low thermal shrinkage rate as compared with conventional inflation molded films. Specifically, the film thickness difference of an average film thickness of 8 to 30 μm is 1 to 3 μm, and the thermal contraction rate is 0.1% or less in MD (machine direction) and 0.15% or less in TD (width direction) [this specification In the book, the film thickness difference is a value obtained by measuring the thickness of the center and both ends in the width direction of the polybutylene terephthalate film at two points, a total of 6 points, and calculating the difference between the maximum value and the minimum value. is there. A smaller value means a better result. The thermal shrinkage is a value obtained by measuring the shrinkage of MD and TD when a polybutylene terephthalate film is exposed at 150 ° C. for 10 minutes. ]. For this reason, a printed layer and a metal vapor deposition layer with little unevenness can be formed. In addition, there is little change in film dimensions in secondary processing such as heat sealing and printing.
[0063]
The heat shrinkage rate of the polybutylene terephthalate film produced by the air-cooled inflation molding method described in [1] (1) above is low as described above, by cooling the region from the neck of the bubble to the frost line, Since the upper bubble region is maintained above the glass transition temperature to the glass transition temperature + 65 ° C or lower while stretching in the longitudinal (MD) and transverse (TD) directions, the resulting bubbles are not distorted (stressed). it is conceivable that.
[0064]
In particular, after air-cooled inflation molding, the film thickness difference of the average film thickness of 3 to 30 μm subjected to the cold stretching described in the above [1] (1) is 1 to 2 μm, and the thermal shrinkage rate in the cold stretching direction is 1. % Or less. Moreover, there is no tearability in any direction, and the mechanical strength is excellent.
[0065]
The polybutylene terephthalate film subjected to cold drawing has innumerable fine linear wrinkles extending in the cold drawing direction. That is, when the surface unevenness of the polybutylene terephthalate film subjected to cold drawing is measured by AFM (Atomic Force Microscope), the height difference of the uneven structure is usually 50 to 500 nm, and the width of the uneven structure (between the vertices of the linear wrinkles) The interval is usually 500 to 20000 nm. However, when biaxial cold stretching is performed sequentially in the machine direction and the transverse direction, the linear wrinkles due to the cold stretching performed earlier disappear, and only the linear wrinkles due to the subsequent cold stretching are the surface of the polybutylene terephthalate film. Remain in. Therefore, even if it performs sequential biaxial cold drawing, the direction of the linear wrinkle which a polybutylene terephthalate film has is only one direction.
[0066]
The polybutylene terephthalate film subjected to cold stretching has a function of diffracting / scattering light by having the linear wrinkles as described above. For example, when a light source such as a light bulb is viewed through a polybutylene terephthalate film having linear wrinkles, a single streak of light having the same width as the light source is observed in the direction perpendicular to the direction of the linear wrinkles. The Therefore, a decorative illumination light or the like can be produced by combining a polybutylene terephthalate film having linear wrinkles and a light source. A laminate in which a plurality of polybutylene terephthalate films having linear wrinkles are bonded so that the directions of the linear wrinkles are different from each other has a large light diffraction / scattering effect. Such a laminate may be useful as a transparent film layer of a transparent electromagnetic wave shielding film obtained by laminating an electromagnetic wave shielding layer on a transparent film. Furthermore, there is a possibility that the laminate itself of the polybutylene terephthalate film having linear wrinkles can be used as an electromagnetic wave shielding film. In particular, a honeycomb structure with a plurality of corrugated polybutylene terephthalate films with linear wrinkles is considered to have a greater light diffraction / scattering effect and a higher transparent electromagnetic shielding property. It is done. Such a honeycomb structure may be useful as a soundproofing material.
[0067]
(2) Simultaneously biaxially stretched film
The polybutylene terephthalate film produced by the simultaneous biaxial stretching method described in [1] and (2) above is transparent, and has excellent film thickness uniformity and thermal shrinkage compared to conventional stretched films. Low. Specifically, the film thickness difference of an average film thickness of 8 to 30 μm is 1 to 2 μm, and the thermal contraction rate is MD (machine direction) 0.25% or less and TD (width direction) 0.5% or less.
[0068]
(3) Shape memory
The polybutylene terephthalate resin has shape memory as described in Japanese Patent Application No. 2002-303500, for example. There are roughly two methods for storing a specific shape in the polybutylene terephthalate film. In the first method, the polybutylene terephthalate film is heated at a temperature T equal to or lower than the glass transition temperature.₁After cold working to primary shape (I), temperature T exceeding the glass transition temperature₂While maintaining the secondary shape (I) at a rapid annealing, then the temperature T below the glass transition temperature_ThreeCool down quickly. The resulting film appears to have a secondary shape (I), but T₁At the above temperature, the primary shape (I) is almost recovered. Even if the polybutylene terephthalate film is fixed to the secondary shape (I) in the annealing and quenching processes, the T₁The reason for recovering the primary shape (I) under the above temperature is not clear, but for example, the temperature T₁During the cold working, strain is retained in the entanglement of polymer chains, and most of this strain is₂T₁It can be considered that the primary shape (I) is recovered under the above temperature.
[0069]
In the second method, the polybutylene terephthalate film is heated at a temperature T above the glass transition temperature to below the melting point._FiveAfter heat-deformation with external force applied at, temperature T below the glass transition temperature without applying external force₆And fixed to the primary shape (II), and further glass transition temperature super to temperature T_FiveLess than temperature T₇The secondary shape (II) is obtained by applying heat and deforming with external force at a temperature T below the glass transition temperature while maintaining the secondary shape (II).₈To fix the secondary shape (II). Temperature T with no external force applied to this_FiveWhen the temperature is higher than the melting point and lower than the melting point, the primary shape (II) is recovered. Even if the polybutylene terephthalate film is fixed to the secondary shape (II) in the heating deformation process and the cooling process, T_FiveThe reason for recovering the primary shape (II) under the above temperature is not clear, but for example, temperature T_FiveIn the heat deformation process, the crystallization of the polymer is promoted, and the crystallization part is entangled to generate a fixed point.₇Temperature T_FiveA part of the deformation is relaxed to form the secondary shape (II), but the orientation of most molecular chains does not change, so that the shape memory may be retained. The degree of crystallinity of the polybutylene terephthalate resin is usually about 20-30%. In addition, the polybutylene terephthalate resin has a large change in elastic modulus around the glass transition temperature.
[0070]
The polybutylene terephthalate film of the present invention produced by the air-cooled inflation molding method and the simultaneous biaxial stretching method described in the above [1] has excellent film thickness uniformity and a low heat shrinkage rate as described above. For this reason, when the primary shape (I) or (II) is memorized by the first or second method for the polybutylene terephthalate film of the present invention, the secondary shape (I) or (II) may be fixed. Each primary shape (I) or (II) can be almost reproduced, and exhibits excellent shape recovery ability (shape memory property).
[0071]
[3] shape memory polybutylene terephthalate film laminate
Since the polybutylene terephthalate film of the present invention is excellent in shape memory properties, it is useful for applications such as packaging materials. However, for use as a packaging material, a shape memory polybutylene obtained by laminating a film-like molded article containing at least one selected from the group consisting of a paper sheet, another thermoplastic resin film and a metal foil, and a polybutylene terephthalate film. A terephthalate film laminate is preferred. Hereinafter, a method for producing a shape memory polybutylene terephthalate film laminate will be described in detail with reference to the drawings.
[0072]
(1) Manufacturing method
(a) First manufacturing method
The first manufacturing method of the shape memory polybutylene terephthalate film laminate includes the following steps (a) to (c).
(A) Adhering a polybutylene terephthalate film and a film-like molded product, and using the polybutylene terephthalate surface of the resulting laminate as a contact surface, while sliding in contact with a cold working roll, the glass transition temperature of the polybutylene terephthalate film or less Temperature T₁Thus, a cold-worked laminate having a curl shape is produced by cold working along the outer shape of the cold-working roll.
(B) While maintaining the obtained curled laminate flat between two nip rolls, the temperature T exceeds the glass transition temperature by contacting with heated air.₂And rapidly anneal to make it look almost flat.
(C) A temperature T below the glass transition temperature of the curled laminate that is apparently substantially flat._ThreeQuickly cool to approximately flat state.
[0073]
The shape memory polybutylene terephthalate film laminate produced by the processing steps (a) to (c) is T₁The curl shape is substantially recovered by the shape recovery ability at the above temperature.
[0074]
FIG. 7 is a schematic side view showing an example of an apparatus for producing a shape memory polybutylene terephthalate film laminate. A film 401 rewound from a reel 410 wound with a polybutylene terephthalate film is fed with an adhesive (for example, hot melt) 456 on one surface of a gravure roll 421, 421 through a guide roll 420, and a drying furnace. At 423, the adhesive layer is dried. After that, the film-like molded body 413 passes between the cooling roll 425 and the rubber roll 425 ′ through the molten polyethylene 455 extruded from the die 422 via the pressure adjusting roll 424 (extrusion lamination). The obtained laminate was slidably contacted with a cold working roll 426 while the temperature T was below the glass transition temperature of the polybutylene terephthalate film.₁Cold processed. This imparts curl properties to the polybutylene terephthalate film layer of the laminate. The temperature of the cold-working roll 426 is such that the temperature of the polybutylene terephthalate layer of the laminated body in sliding contact is T₁Adjust so that The obtained curled laminate 411 is held flat between the two nip rolls 427 and 427 ′, and is heated to a temperature T exceeding the glass transition temperature by heated air from the heater 429.₂At a temperature T equal to or lower than the glass transition temperature by contact with a cooling roll 428._ThreeCooled by. The temperature of the cooling roll 428 is such that the temperature of the polybutylene terephthalate layer of the laminated body in sliding contact is T_ThreeAdjust so that Thereafter, the curled laminate is wound up at room temperature by a take-up reel with the film-like molded body layer as the inside, whereby a wound film 412 (shape memory polybutylene terephthalate film laminate 450) is obtained.
[0075]
Temperature T above the glass transition temperature while holding the curled laminate flat₂The rapid annealing process must be performed to such an extent that the curling property imparted by the cold working is not lost. Temperature T₂Is preferably above 45 ° C and below 65 ° C. It is rapidly heated to this temperature range and annealed for 30-60 seconds. The tension applied to keep flat between the two nip rolls 427 and 427 'is 5 to 10 kgf / m width. The temperature setting of the heaters 429 and 429 is the temperature T of the polybutylene terephthalate film layer of the curled laminate 411.₂To be heated. In FIG. 7, the heaters 429 and 429 are heated from both sides of the curled laminate 411, but the heater 429 may be installed only on the polybutylene terephthalate film layer side of the curled laminate 411. The heated air emitted from the heater 429 may be sprayed onto the polybutylene terephthalate film layer of the curlable laminate 411 using a nozzle.
[0076]
The resulting shape memory polybutylene terephthalate film laminate is T₁The curled shape is recovered by leaving or treating under the above temperature conditions. In the example shown in FIG._ThreeAfter cooling, the film-like molded body layer is wound up as the inner side. The curled laminate 411 fixed substantially flat in the steps (b) to (c) above is further used as a wound film 412, so that the shape memory polybutylene terephthalate film laminate 450 is kept almost flat when stored. it can. Therefore, the curled laminate 411 when the wound film 412 (shape memory polybutylene terephthalate film laminate 450) is rewound is substantially flat.
[0077]
Cold working temperature T₁Is essential to be not higher than the glass transition temperature of the polybutylene terephthalate film, but is preferably not higher than 35 ° C., more preferably 15 to 25 ° C. Temperature T for cooling the curled laminate 411 after annealing_ThreeIs essential to be not higher than the glass transition temperature, but is preferably 15 to 25 ° C.
[0078]
The film-like molded product laminated on the polybutylene terephthalate film can be appropriately selected from paper sheets, other thermoplastic resin films, metal foils, etc. according to the use of the shape memory polybutylene terephthalate film laminate, A laminated sheet by a combination of these may be used. As a film-like molded article, (1) a paper sheet, an adhesive layer comprising an adhesive layer and an extrusion-laminated polyethylene layer, and a sealant film in this order, or (2) a paper sheet, an adhesive layer ( A) and an extrusion-laminated polyethylene layer (b), a polyethylene terephthalate film layer, an adhesive layer (b) and an extrusion-laminated polyethylene layer (b) And those having a sealant film in this order.
[0079]
Regarding how to wind the polybutylene terephthalate film 401 around the cold-working roll 426, as shown in FIG. 7, the angle θ formed by the winding direction and the unwinding direction of the polybutylene terephthalate film 401₁Is preferably in the range of 45 to 60 °. Thereby, sufficient curling property can be imparted to the polybutylene terephthalate film 401. Angle θ₁Can be adjusted to a desired value by appropriately adjusting the positional relationship between the cold working roll 426 and the pressure adjusting roll 424 '.
[0080]
When the polybutylene terephthalate film 401 and the film-shaped molded body 413 are bonded through the cooling roll 425 and the rubber roll 425 ′, the polybutylene terephthalate film 401 is usually applied with a tension of 4 kgf / m width or more by the pressure adjusting roll 424. Do. In particular, by applying a tension of 10 to 20 kgf / m width to the polybutylene terephthalate film 401, the polybutylene terephthalate film 401 can be adhered to the film-like molded body 413 while being stretched in the machine direction to an elastically stretchable elongation. As a result, the polybutylene terephthalate film 401 is bonded to the film-like molded body 413 in an expanded state while maintaining an elastic restoring force. The stretched state that retains the elastic restoring force is a state in which the polybutylene terephthalate film 401 retains the force to shrink to the original shape when the force to fix the stretching of the polybutylene terephthalate film 401 is released. . For this reason, the curl property of the shape memory polybutylene terephthalate film laminate 450 can be further improved. In this specification, the curling property means the property that the shape memory polybutylene terephthalate film laminate 450 can be warped, unlike the dead hold property that can be maintained in a state where the shape memory polybutylene terephthalate film laminate 450 is warped. To do. The elastic stretchable elongation is generally an elongation that is stretched by about 1 to 3% to such an extent that the polybutylene terephthalate film does not appear wrinkled by stretching.
[0081]
The diameter of the cold working roll 426 is preferably 20 to 80 cm. Thereby, sufficient curling property can be imparted to the polybutylene terephthalate film 401. Usually, the peripheral speed of the cold working roll 426 is 30 to 100 m / min.
[0082]
In the example shown in FIG. 7, the polybutylene terephthalate film and the film-shaped molded body are bonded by an extrusion lamination method, but may be bonded by a dry lamination method. In the example shown in FIG. 7, the film-shaped molded body 413 is bonded to only one side of the polybutylene terephthalate film 401. Can also be given.
[0083]
FIG. 8 is a schematic side view showing another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate. In addition, the same reference number is attached | subjected to the same member or part as the Example shown in FIG. This example is the same as the example shown in FIG. 7 except that the polybutylene terephthalate film 401 and the film-like molded body 413 are bonded together by a dry lamination method. The polybutylene terephthalate film 401 provided with the adhesive layer passes through the pressure adjusting roll 424 and passes between the pair of heating rolls 438 and 438 while the film-shaped molded body 413 is overlapped with the adhesive layer. Therefore, the adhesive layer between the polybutylene terephthalate film 401 and the film-like molded body 413 is only an adhesive layer. However, since it is preferable that the adhesive strength is higher, it is preferable to bond the polybutylene terephthalate film 401 and the film-like molded body 413 by the extrusion lamination method shown in FIG. The film-shaped molded body 413 may be formed by either extrusion lamination method or dry lamination method, but is preferably formed by extrusion lamination method.
[0084]
(b) Second manufacturing method
The second manufacturing method of the shape memory polybutylene terephthalate film laminate includes the following steps (d) to (f).
(D) (i) A laminate was prepared in advance by adhering a polybutylene terephthalate film and a film-shaped molded article, and the polybutylene terephthalate film was slidably contacted with a heating roll using the polybutylene terephthalate film surface as a contact surface. Temperature T above glass transition temperature to below melting point_Five(Ii) The temperature T while sliding the polybutylene terephthalate film on the heating roll._FiveThus, a deformation process is performed along the outer shape of the heating roll, and then the film is bonded to a film-like molded body to produce a curled laminate exhibiting a curled shape.
(E) The obtained curled laminate is brought into contact with a cooling roll or cooling air, and a temperature T equal to or lower than the glass transition temperature.₆Cool with.
(F) Next, the film-shaped molded body layer is wound inside at room temperature, and the glass transition temperature is above-temperature T._FiveLess than temperature T₇At a temperature T equal to or lower than the glass transition temperature.₈Then, a wound film-like shape memory polybutylene terephthalate film laminate is produced.
[0085]
The shape memory polybutylene terephthalate film laminate produced by the processing steps (d) to (f) is T_FiveThe curl shape is substantially recovered by the shape recovery ability at the above temperature.
[0086]
The polybutylene terephthalate resin has a glass transition temperature of 22 to 45 ° C., which is close to room temperature, and can be easily heated to a glass transition temperature or higher and cooled to a temperature lower than the glass transition temperature. Moreover, since the melting point is as high as about 230 ° C, the temperature range from the glass transition temperature to the melting point is wide, and the temperature T_FiveAnd temperature T₆The difference can be increased. Therefore, the above operations (d) to (f) can be easily performed. Hereinafter, the second manufacturing method of the shape memory polybutylene terephthalate film laminate will be described in detail with reference to the drawings.
[0087]
FIG. 9 is a schematic side view showing an example of an apparatus for producing the shape memory polybutylene terephthalate film laminate by the second production method. In this example, a film-like molded body is bonded to a polybutylene terephthalate film that has been previously imparted with curling properties. The process until the adhesive 422 is applied to one surface of the polybutylene terephthalate film 401 and the adhesive layer is dried in the drying furnace 423 is the same as the example shown in FIG. As shown in FIG. 9, the polybutylene terephthalate film 401 after the adhesive layer has been dried slides through a pressure adjusting roll 424 to a deformation processing roll 430 that can be heated with a surface having no adhesive layer as a contact surface. The above temperature T_FiveThe curling property is imparted by the deformation process. The temperature of the deformation processing roll 430 is such that the temperature of the polybutylene terephthalate layer of the laminated body in sliding contact is T._FiveAdjust so that Thereafter, the film-like molded body 413 passes between the deformation processing roll 430 and the abutting roll 430 ′ that contacts the deformation processing roll 430 while being overlapped with the adhesive layer of the polybutylene terephthalate film 401. Is done. The obtained curled laminate 411 is brought into contact with the cooling roll 428, so that the temperature T below the glass transition temperature.₆Then, the film is formed into a wound film 412 by being taken up at room temperature by a take-up reel with the film-like molded body layer of the curled laminate as the inner side. The temperature of the cooling roll 428 is such that the temperature of the polybutylene terephthalate layer of the laminated body in sliding contact is T₆Adjust so that The obtained wound film 412 is above the glass transition temperature to temperature T_FiveLess than temperature T₇At a temperature T equal to or lower than the glass transition temperature.₈The shape memory polybutylene terephthalate film laminate 450 is obtained by being cooled in the above. After making the wound film 412, the temperature T₇Heat treatment at temperature T₈By cooling at, the curled shape of the laminate is made latent and an apparently substantially flat laminate is obtained. There is no limitation on the means for heating / cooling the wound film 412, and examples include a method of putting the wound film 412 in a tank and heating the periphery of the tank with a heater or cooling with a cooling device. The temperature control of the heater and cooling device is such that the temperature of the wound film 412 is the temperature T₇Or temperature T₈To be.
[0088]
The resulting shape memory polybutylene terephthalate film laminate has a temperature T_FiveThe curl shape is recovered by heat treatment at a temperature lower than the melting point of the polybutylene terephthalate film. In addition, in the example shown in FIG. 9, in order to make it a substantially flat shape as a secondary shape, the film-like molded body layer of the curled laminate is wound up inside, but this makes the film efficient and flat. Can do.
[0089]
Heating temperature T in deformation processing roll 430_FiveAlthough it is essential that the temperature be higher than the glass transition temperature of the polybutylene terephthalate film to less than the melting point, it is preferably 75 to 100 ° C, more preferably 90 to 100 ° C. Cooling temperature T in cooling roll 428₆Although it is essential that the temperature be lower than the glass transition temperature, it is preferably 40 ° C. or lower. The curled laminate 411 may be cooled by using cooling air instead of the cooling roll 428. Temperature T for heating the wound film 412₇Is above the glass transition temperature to T_FiveHowever, it is preferably 45 to 65 ° C, more preferably 45 to 50 ° C. Also temperature T₇The heat treatment at is preferably performed for about 24 hours. Cooling temperature T after heat treatment of wound film 412₈Is essential to be not higher than the above glass transition temperature, but is preferably not higher than 40 ° C.
[0090]
Regarding how to wind the polybutylene terephthalate film 401 around the deformation roll 430, the angle θ formed by the winding direction and the unwinding direction of the polybutylene terephthalate film 431 shown in FIG.₂Is preferably in the range of 45 to 60 °. Thereby, sufficient curling property can be imparted to the polybutylene terephthalate film 401. Angle θ₂Can be adjusted to a desired value by appropriately adjusting the positional relationship between the deformation processing roll 430 and the pressure adjusting rolls 424 and 424.
[0091]
As described in the first manufacturing method in (a) above, the polybutylene terephthalate film 401 and the film-like molded body 413 are bonded by passing between the deformation processing roll 430 and the contact roll 430 ′. At this time, it is performed while applying a tension of usually 4 kgf / m width or more to the polybutylene terephthalate film 401 by the pair of pressure adjusting rolls 424 and 424. Similar to the first production method, it is preferable to apply a tension of 10 to 20 kgf / m width to the polybutylene terephthalate film 401.
[0092]
The diameter of the deformation roll 430 is preferably 60 to 80 cm. Thereby, sufficient curling property can be imparted to the polybutylene terephthalate film 401. Usually, the peripheral speed of the deformation processing roll 430 is 30 to 100 m / min.
[0093]
FIG. 10 is a schematic side view showing another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate by the second production method. In addition, the same reference number is attached | subjected to the same member or part as the Example shown in FIG. In this example, a polybutylene terephthalate film and a film-shaped molded body are bonded in advance to produce a laminate, and then the curl property is imparted to the polybutylene terephthalate film layer. The process until the polybutylene terephthalate film 401 and the film-like molded body 413 are bonded by a pair of heating rolls 438 and 438 is the same as the example shown in FIG. The resulting laminate was in sliding contact with the roll 430 for deformation processing while the temperature T was above the glass transition temperature of the polybutylene terephthalate film to below the melting point T._FiveIs deformed. This imparts curl properties to the polybutylene terephthalate film layer of the laminate. The obtained curled laminate 411 is brought into contact with the cooling roll 428, so that the temperature T below the glass transition temperature.₆Then, the film is formed into a wound film 412 by being wound at room temperature by a take-up reel with the film-like molded body layer of the curlable laminate 411 as the inner side. The obtained wound film 412 is above the glass transition temperature to temperature T_FiveLess than temperature T₇At a temperature T equal to or lower than the glass transition temperature.₈The shape memory polybutylene terephthalate film laminate 450 is obtained by being cooled in the above.
[0094]
In the embodiment shown in FIG. 10, the temperature T_Five~ T₈The requirements regarding are the same as those of the embodiment shown in FIG. Angle θ formed by the winding direction and unwinding direction of laminate 411_ThreeIs preferably in the range of 45 to 60 °.
[0095]
In the example shown in FIG. 10, the film-shaped molded body 413 is bonded to only one side of the polybutylene terephthalate film 401. However, after the film-shaped molded body 413 is bonded to both surfaces of the polybutylene terephthalate film 401, the shape memory is stored. It is also possible to impart sex.
[0096]
(c) Third manufacturing method
FIG. 11 is a schematic side view showing still another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate. In addition, the same reference number is attached | subjected to the same member or part as the Example shown in FIG. First, a polybutylene terephthalate film and a film-shaped molded body are bonded by an extrusion lamination method or a dry lamination method to form a laminate having a film-shaped molded body on one side or both sides of the polybutylene terephthalate film (not shown). The obtained laminated body 414 passes through the pressure adjusting rolls 424 and 424, while the pressing die 430 for imparting the tray shape is pressed against the temperature T₁And the deformation along the outer shape of the pressing die 430 is intermittently applied. The obtained deformed laminate 415 is passed between a pair of annealing rolls 431 and 431, and the temperature T₂Is rapidly flattened by rapid annealing, and then the temperature T is set by the cooling devices 432 and 432._ThreeIt is cooled rapidly. The substantially flattened deformable laminate 415 is wound up at room temperature while being laminated with the coating film 416 by a winding roll 433 of the same type as the pressing die 430 to form a wound film. As a result, the deformation along the outer shape of the pressing die 430 is made latent, and a laminated body having no apparent deformation is obtained. Temperature T performed while pressing the mold 430 against the polybutylene terephthalate film 401₁The cold working in may be performed for 10 to 60 seconds. In the example shown in FIG. 11, a tray-shaped pressing mold 430 is used, but a pressing mold having a desired shape for which shape storage is desired can be used.
[0097]
(2) Layer structure of shape memory polybutylene terephthalate film laminate
As shown in FIG. 12, a typical shape memory polybutylene terephthalate film laminate comprises a polybutylene terephthalate film layer 551, a paper sheet layer 552, and a sealant film layer 554. Hereinafter, each layer will be described in detail.
[0098]
(a) Polybutylene terephthalate film layer
By using the polybutylene terephthalate film of the present invention, a shape memory polybutylene terephthalate film laminate capable of stably reproducing the applied shape can be obtained. The thickness of the polybutylene terephthalate film is preferably 6 μm or more, more preferably 10 to 50 μm, and even more preferably 10 to 30 μm. If the thickness of the polybutylene terephthalate film is 6 μm or more, it has sufficient shape memory ability, aroma retention and gas barrier properties, as well as good glossiness and printing characteristics.
[0099]
When the shape memory polybutylene terephthalate film laminate is used as a packaging material for a lid of an instant food container, a large number of polybutylene terephthalate films before being bonded to the film-like molded product are obtained by the method described later in [4]. It is preferable to form a substantially parallel linear trace. Thereby, linear easy tearability can be provided to the polybutylene terephthalate film, and the lid can be partially opened.
[0100]
(b) Paper sheet layer
It is preferable that the shape memory polybutylene terephthalate film laminate also has a layer made of a paper sheet as a dead hold property imparting layer. The paper type of the paper sheet layer 552 is not limited and includes synthetic paper. The thickness of the paper sheet layer 552 is about 60 to 110 g / m.²It is preferably about 75 to 90 g / m.²Is more preferable. The thickness of the paper sheet 552 is about 60 g / m²If it is less than 1, the waist of the paper sheet 552 is too weak to provide sufficient dead hold property. Meanwhile, the thickness of the paper sheet 552 is about 110 g / m²Even if it exceeds the maximum, only the cost increases and no further improvement in dead hold property is recognized.
[0101]
(c) Sealant film layer
When the shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container, the shape memory polybutylene terephthalate film laminate is provided with a sealant film layer 554 for heat sealing the upper end flange portion of the container body. The sealant film layer 554 can be formed of a polyethylene film, an unstretched polypropylene film, an ionomer resin film, a polystyrene film, or the like. The sealant film 554 preferably has an easy peel property so that the lid can be easily peeled off from the container body. Therefore, it is preferable that the sealant film 554 has a relatively weak thermal adhesiveness. Moreover, a well-known hot melt can also be used as a heat sealing material.
[0102]
As the sealant film 554, for example, a laminated film of a polyethylene base film on the paper sheet 552 side and a low molecular weight polyethylene film on the upper end flange portion side of the container body can be used. The thickness of the polyethylene base film is preferably about 10 to 40 μm, more preferably about 20 to 30 μm. The thickness of the low molecular weight polyethylene film is preferably about 5 to 20 μm, more preferably about 7 to 15 μm. Such a laminated polyethylene film is commercially available, for example, as 760FD (manufactured by Toray Synthetic Film Co., Ltd.). As the sealant film 554, a film made of a mixture of ethylene-vinyl acetate copolymer (EVA) and polyethylene can also be used. In the film made of this mixture, linear low density polyethylene (LLDPE) is preferable as the polyethylene. The thickness of the film made of this mixture is also preferably about 10 to 40 μm, more preferably about 20 to 30 μm. The thickness of the hot melt layer is preferably 10 to 50 μm, more preferably 20 to 40 μm.
[0103]
As the sealant film layer 554, the one disclosed in Japanese Patent Application No. 2002-183197 may be used. The sealant film disclosed in Japanese Patent Application No. 2002-183197 is obtained by copolymerizing ethylene and an α-olefin having 3 to 18 carbon atoms, and has a density (JIS K6922) of 0.870 to 0.910 g / cm.^Three, MFR (JIS K6921, 190 ° C., 2.16 kg load) is a resin composition containing a linear ethylene / α-olefin copolymer and polystyrene having a weight of 1 to 100 g / 10 min. Thereby, even if the sealing surface of a container main body is either polyethylene or a polystyrene, the multi-sealant layer which can make sealing performance and easy-openability compatible can be formed by heat-sealing a cover body.
[0104]
Specifically, as the linear ethylene / α-olefin copolymer, a binary copolymer obtained by copolymerizing ethylene and one kind of α-olefin having 3 to 18 carbon atoms, and ethylene and 2 Examples thereof include terpolymers obtained by copolymerizing various kinds of α-olefins having 3 to 18 carbon atoms. Examples of the α-olefin having 3 to 18 carbon atoms include propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, and the like. You may use above.
[0105]
The linear ethylene / α-olefin copolymer has a density of 0.870 g / cm^ThreeIf it is less than the above, the blocking property is poor, there is a possibility of elongation or breakage at the time of forming the sealant film, and the cut property of the film is also inferior. On the other hand, the density is 0.910 g / cm^ThreeExceeding is inferior in adhesion to the sealing surface of the container. Preferred density is 0.875-0.905 g / cm^ThreeIt is.
[0106]
In addition, linear ethylene / α-olefin copolymers have a melt viscosity that is too high when the MFR is less than 1 g / 10 min, and thus the extensibility during extrusion is insufficient, and the melt viscosity exceeds 100 g / 10 min. Since it is too low, the neck-in is large and the moldability is poor. The preferred MFR is 2-80 g / 10 min.
[0107]
The linear ethylene / α-olefin copolymer can be produced by polymerization using a known titanium-based catalyst or metallocene catalyst, but high pressure ion polymerization, gas phase polymerization or It is preferable to use a copolymer produced by solution polymerization.
[0108]
Examples of the metallocene catalyst include JP-A-58-19309, JP-A-59-95292, JP-A-60-35005, JP-A-60-35006, JP-A-60-35007, and JP-A-60. -35008, JP-A 60-35009, JP-A 61-130314, JP-A 3-163088, European Patent Application Publication No. 420,436, US Patent No. 5,055,438, International Publication WO91 / The metallocene catalyst or metallocene / alumoxane catalyst described in the specification of No. 04257 or the like, or the metallocene compound disclosed in, for example, International Publication No. WO92 / 07123, etc. The catalyst which consists of a compound used as ion can be mentioned.
[0109]
Specific examples of such linear ethylene / α-olefin copolymers include trade names “Kernel KF-360”, “Kernel KF-365”, and “Kernel KC-650” (all of which are manufactured by Nippon Polychem Co., Ltd.) Manufactured) and the like.
[0110]
As the polystyrene, so-called general-purpose polystyrene resins, rubber-modified polystyrene resins, and mixtures thereof can be used. As a general-purpose polystyrene resin, a styrene homopolymer is usually used. The rubber-modified polystyrene resin is obtained by polymerizing a styrene monomer in the presence of a rubbery polymer such as butadiene rubber. As the molecular structure of polystyrene, either a linear type or a branched type may be used. Polystyrene can be made into a branched type by copolymerizing with a polyfunctional vinyl monomer such as divinylbenzene, or by polymerization using a polyfunctional initiator, a polyfunctional chain transfer agent or the like.
[0111]
As a styrene monomer used for polymerization of general-purpose polystyrene resin or rubber-modified polystyrene resin, styrene is generally used, but alkyl such as α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, etc. Substituted styrene can also be used. Specific examples of polystyrene include trade names “PSP-G930”, “HIPS-475D”, “HIPS-HT516” (all manufactured by A & M Polystyrene Co., Ltd.) and the like.
[0112]
When the sealant film contains polystyrene, not only the multi-sealant layer can be formed, but also a tearability improving effect, an antiblocking effect, an antistatic effect and the like are exhibited.
[0113]
The blending ratio of the linear ethylene / α-olefin copolymer and polystyrene is such that the weight ratio of (linear ethylene / α-olefin copolymer) :( polystyrene) is 50:50 to 90:10. Is more preferable, and 75:25 to 85:15 is more preferable.
[0114]
When the total of the linear ethylene / α-olefin copolymer and polystyrene is 100% by weight and the proportion of the linear ethylene / α-olefin copolymer exceeds 90% by weight, the sealing surface of the container body is made of polystyrene resin. In some cases, the adhesive strength is not sufficient. On the other hand, when the proportion of polystyrene exceeds 50% by weight, the adhesive strength becomes insufficient when the sealing surface is a polyethylene resin layer.
[0115]
The resin composition containing a linear ethylene / α-olefin copolymer and polystyrene has a density of 0.910 to 0.940 g / cm in order to adjust adhesion, film strength and the like.^ThreeIt is preferable that the resin further contains an ethylene resin having an MFR of 1 to 50 g / 10 min. Examples of such an ethylene-based resin include high-pressure low-density polyethylene, linear low-density ethylene copolymer, and ethylene / vinyl acetate copolymer. The blending ratio of the ethylene-based resin is preferably 10 to 30% by weight based on 100% by weight of the entire resin composition constituting the sealant film. A lubricant, an anti-blocking agent, a stabilizer, an antistatic agent, a colorant, and other various additives may be added to the resin composition as necessary.
[0116]
A sealant film comprising a resin composition containing a linear ethylene / α-olefin copolymer and polystyrene as described above is obtained by, for example, melting linear ethylene / α-olefin copolymer, polystyrene and ethylene-based resin. The film can be formed by a method such as extrusion from a T die. The thickness of the sealant film thus obtained is preferably about 10 to 40 μm, more preferably about 20 to 30 μm.
[0117]
In order to impart easy opening (easy tearing), a number of substantially parallel linear marks may be formed on the sealant film 554 on at least one surface by the method described later in [4]. In this case, the sealant film layer 554 is provided so that the tear direction of the lid and the linear mark direction of the sealant film coincide.
[0118]
In order to impart easy opening (easy tearing), an infinite number of fine holes may be provided in at least the tear region of the sealant film 554. The fine holes may or may not penetrate through the sealant film 554. In general, the fine pores have an average opening diameter of 0.5 to 100 μm, and the density in the tear region is about 500 holes / cm.²The above is preferable. The density of micropores is about 500 / cm²If it is less than 1, the tearability is insufficient. The upper limit of the fine pore density is not particularly limited as long as it is technically possible. In order to form fine holes in the sealant film 554, for example, methods disclosed in Japanese Patent No. 2071842 and Japanese Patent Laid-Open No. 2002-059487 are employed.
[0119]
(d) Light-shielding ink layer
When the shape memory polybutylene terephthalate film laminate needs light shielding properties, a light shielding ink layer 553 is provided as shown in FIG. In the example shown in FIG. 14, an ink layer-forming PET film in which a light-shielding ink layer 553 is previously printed on a polyethylene terephthalate (PET) film is prepared and provided on the outer surface of the sealant film layer 554. As such a PET film, for example, a biaxially oriented polyethylene terephthalate (PET) film having a uniaxial orientation or a different orientation degree, which is commercially available as “Emblet PC” (Unitika Ltd.), can be used. Further, the light-shielding ink layer 553 can be provided on the inner surface of the polybutylene terephthalate film layer 551, or can be provided on one surface of the paper sheet layer 552 (for example, the inner surface of the paper sheet layer 552) (not shown). ). The light-shielding ink is not particularly limited as long as it is an ink containing a black or dark pigment or dye such as carbon black. The thickness of the light-shielding ink layer 553 depends on the concentration of the black pigment or dye in the ink, but generally only needs to be sufficient to block ultraviolet rays and visible light. In this specification, the “outer surface” and the “inner surface” are the outer surface and the inner surface of the container when the shape memory polybutylene terephthalate film laminate is used as a lid for an instant food container or the like. Means.
[0120]
(e) Layer configuration example
12 to 14 exemplify a layer structure when the curled shape memory polybutylene terephthalate film laminate 550 is used as a packaging material for a lid of an instant food container. The laminated body shown in FIG. 12 shows a layer structure composed of a polybutylene terephthalate film layer 551, a paper sheet 552, and a sealant film layer 554 as a basic structure. Between the polybutylene terephthalate film layer 551 and the paper sheet 552, there is an adhesive layer (I) consisting of an adhesive layer 556 and an extruded laminated polyethylene layer (I) 555, and the paper sheet 552 and the sealant film layer 554 Between them is an adhesive layer (II) consisting of an adhesive layer 556 'and an extrusion-laminated polyethylene layer (II) 555'. In the case of the layer configuration shown in FIG. 12, the outer layer is composed of the polybutylene terephthalate film 551 and the adhesive layer (I) (555 and 556), the adhesive layer (II) (555 ′ and 556 ′), and the sealant film 554. The layer thickness ratio with the inner layer (A) is preferably outer layer / inner layer (A) = 100/35 to 100/100. Thereby, the dead hold property of the polybutylene terephthalate film 551 can be functioned effectively.
[0121]
FIG. 13 shows an example in which a polyethylene terephthalate layer 557 is provided between the paper sheet layer 552 and the sealant film layer 554 in order to increase the rigidity of the shape memory polybutylene terephthalate film laminate and to give good shape memory ability. . In FIG. 13, 555 ″ indicates an extrusion-laminated polyethylene layer (III), and 556 ″ indicates an adhesive layer (III). FIG. 14 shows an example in which a light-shielding ink layer 553 is provided on the inner surface of the polyethylene terephthalate layer 557 in order to impart good light-shielding properties.
[0122]
15 and 16 show representative examples of the layer configuration of a shape memory polybutylene terephthalate film laminate constituting a lid used for a container for containing semi-solid food such as jelly and pudding. The laminate shown in FIG. 15 includes a polybutylene terephthalate film layer 551, a rigid film layer layer 557, and a sealant film layer 554 as a basic configuration. There is an adhesive layer (for example, a hot melt layer) 556 between the polybutylene terephthalate film layer 551 and the rigid film layer 557, and an adhesive layer (for example, a hot melt layer) between the paper sheet 552 and the sealant film layer 554. ) 556 '. FIG. 16 shows an example in which a light-shielding ink layer 553 is provided on the inner side surface of the rigid film layer 557 in order to impart good light-shielding properties.
[0123]
The lid used for containers for storing semi-solid foods does not require resealability after pouring, unlike the lids used for instant food containers. Often does not have. However, if the laminate is constructed by adhering only two layers of a polybutylene terephthalate film and a polyethylene film, the curling property imparted to the polybutylene terephthalate film is easily absorbed by the polyethylene film, and the shape memory property may be insufficient. There is. Therefore, when manufacturing a shape memory polybutylene terephthalate film laminate having a polybutylene terephthalate film layer and a polyethylene film layer, a polyethylene terephthalate film, a biaxially stretched polypropylene film (between the polybutylene terephthalate film layer and the polyethylene film layer ( It is preferable to provide a layer made of a rigid film such as an OPP film) or a nylon film.
[0124]
[4] Line mark formation
In the polybutylene terephthalate film of the present invention, a plurality of substantially parallel linear marks are formed on at least one surface by the method described below, thereby making it easy to linearly stretch in one direction regardless of the orientation of the film. Cleavage can be imparted. Thereby, it can be torn linearly from any part along the linear trace. When a packaging bag is manufactured using a linear easily tearable polybutylene terephthalate film, it can be opened in a strip shape without a taper while maintaining a certain width. The linear easily tearable polybutylene terephthalate film has excellent gas barrier properties because no linear traces penetrate. When the shape memory polybutylene terephthalate film laminate described in [3] above is used as a packaging material for a lid of an instant food container, it is linear with respect to the polybutylene terephthalate film before being bonded to the film-shaped molded body. It is preferable to form a mark. As a result, the lid can be partially opened.
[0125]
A linear easily tearable polybutylene terephthalate film is formed by sliding a continuously running polybutylene terephthalate film on a linear trace forming means having a large number of fine protrusions to form a large number of substantially parallel linear traces. It is manufactured by. Hereinafter, a method for producing a linear easily tearable polybutylene terephthalate film will be described in detail with reference to the drawings.
[0126]
(1) When forming linear marks in the direction of travel on the film
FIG. 17 is a schematic side view showing an example of an apparatus for forming linear marks in the traveling direction of the polybutylene terephthalate film 601. As shown in FIG. FIG. 17 shows an example in which a roll (hereinafter referred to as “pattern roll”) 602 having a large number of fine protrusions on the surface is used as the linear trace forming means, and the nozzle 603 is used as the compressed air blowing means. The polybutylene terephthalate film 601 that has been rewound from the reel 607 wound with the original film is subjected to a nip roll 671 to form a linear mark when contacting the pattern roll 602. The butylene terephthalate film is wound around a take-up reel 675 via a nip roll 672 and guide rolls 673 and 674.
[0127]
As shown in FIG. 18, the pattern roll 602 is fixed at a fixed position so that its rotation axis is parallel to the width direction of the polybutylene terephthalate film 601, and the axial length is the width of the polybutylene terephthalate film 601. The entire width of the polybutylene terephthalate film 601 is in sliding contact with the pattern roll 602.
[0128]
Nip rolls 671 and 672 are provided as tension adjusting rolls before and after the pattern roll 602 so that tension is applied to the polybutylene terephthalate film 601 running on the pattern roll 602. Further, as shown in FIG. 18, the polybutylene terephthalate film 601 is uniformly applied to the sliding contact surface by blowing air with a predetermined wind pressure from the nozzle 603 to the surface (sliding contact surface) where the polybutylene terephthalate film 601 is slidably contacting the pattern roll 602. Contact force can be applied. Thereby, uniform linear traces can be formed on the film surface. By pressing the polybutylene terephthalate film 601 against the pattern roll 602 using the nozzle 603, contact nonuniformity on the sliding contact surface due to uneven thickness of the polybutylene terephthalate film 601 can be reduced. If a rubber roll is used as a means for pressing the polybutylene terephthalate film 601 against the pattern roll 602, the contact force on the sliding contact surface becomes uneven due to uneven thickness of the polybutylene terephthalate film 601. The butylene terephthalate film 601 may be damaged. For this reason, air blowing means such as blowers and nozzles are superior to rubber rolls as means for pressing the polybutylene terephthalate film 601 against the pattern roll 602.
[0129]
The pattern roll 602 is preferably rotated at a peripheral speed slower than the traveling speed of the polybutylene terephthalate film 601 in the direction opposite to the traveling direction of the polybutylene terephthalate film 601. As a result, the generation of film wrinkles can be prevented, and shavings generated due to the formation of linear traces can be prevented from accumulating on the surface of the pattern roll 602, so that linear traces of appropriate length and depth can be formed. This is preferable. The traveling speed of the polybutylene terephthalate film 601 is preferably 10 to 500 m / min. The peripheral speed of the pattern roll 602 (the speed at which the polybutylene terephthalate film 601 is rotated in the direction opposite to the traveling direction) is preferably 1 to 50 m / min.
[0130]
As the pattern roll 602, for example, those described in JP-A-2002-059487 can be used. This has a structure in which a large number of fine particles having a Mohs hardness of 5 or more having sharp corners on the surface of a metal roll main body are adhered by an electrodeposition method or an organic or inorganic binder. The metal roll body is made of, for example, iron or an iron alloy, or a surface coated with a nickel plating layer or a chromium plating layer. Examples of fine particles having a Mohs hardness of 5 or more include cemented carbide particles such as tungsten carbide, silicon carbide particles, boron carbide particles, sapphire particles, cubic boron nitride (CBN) particles, natural or synthetic diamond fine particles, and the like. Can do. In particular, synthetic diamond fine particles having high hardness, strength and the like are desirable. The particle diameter of the fine particles is appropriately selected according to the depth or width of the linear marks to be formed. The fine particles preferably have a particle size of 10 to 100 μm and a particle size variation of 5% or less. The degree to which the fine particles are adhered is appropriately selected so that the interval between the linear marks to be formed becomes a desired degree. In order to obtain uniform linear marks, it is desirable that the fine particles adhere to the roll body surface by 50% or more. As a specific example of the pattern roll 602, a large number of synthetic diamond fine particles having sharp corners on the surface of an iron roll main body are bonded and fixed with a nickel-based electrodeposition layer at an area ratio of 50% or more. Is mentioned. The outer diameter of the pattern roll 602 is preferably 2 to 20 cm, and more preferably 3 to 10 cm.
[0131]
As the pattern roll 602, a needle-tooth roll in which metal needles are regularly embedded in the surface of the metal roll main body at fine intervals can be used. In addition to the pattern roll 602, as the linear scar forming means, a pattern plate having a large number of fine particles having a Mohs hardness of 5 or more and sharp corners on the surface of the plate-like main body is used. It may be used.
[0132]
FIG. 19 is a partial enlarged cross-sectional view showing a state in which the polybutylene terephthalate film 601 is in sliding contact with the pattern roll 602 to form a linear trace. For example, at least one corner of the fine particles 604 on the surface of the pattern roll 602 cuts into the lower surface of the polybutylene terephthalate film 601, but as described above, the traveling speed of the polybutylene terephthalate film 601 is the pattern roll. Since it is faster than the peripheral speed at which 602 rotates in the reverse direction, one long linear mark is formed until the corner of the cut fine particle 604 is separated from the lower surface of the polybutylene terephthalate film 601.
[0133]
As the compressed air blowing means, a plurality of nozzles as shown in FIG. 20 (b) can be used instead of the nozzle having the belt-like outlet 631 (similar to those shown in FIGS. 17 to 19) as shown in FIG. 20 (a). A nozzle having the outlet 631 may be used. As shown in FIG. 20 (c), when compressed air is blown in a form that covers the pattern roll 602 using a nozzle having a hood 632, the compressed air blown from the outlet 631 diffuses until reaching the sliding contact surface. Therefore, the contact force between the polybutylene terephthalate film 601 and the pattern roll 602 on the sliding contact surface can be made more uniform. The pressure of the compressed air flow blown by such compressed air blowing means is 0.05 to 5 kgf / cm.²Is preferred. As a result, the contact force between the polybutylene terephthalate film 601 and the pattern roll 602 on the sliding contact surface can be made uniform. More preferable compressed air flow pressure is 0.1-2 kgf / cm²It is. The distance from the outlet 631 to the sliding contact surface is preferably 10 to 50 cm. The compressed air may be uniformly applied to a range covering at least the sliding contact surface. However, making the blower or nozzle outlet 631 larger than necessary is not preferable because the amount of compressed air required to obtain an appropriate wind pressure increases.
[0134]
About how to wind the polybutylene terephthalate film 601 around the pattern roll 602 fixed at a fixed position, the angle θ formed by the winding direction and the unwinding direction of the polybutylene terephthalate film 601 shown in FIG._FourIs preferably in the range of 60 to 170 °. This makes it easy to adjust the length and depth of the linear trace. Angle θ_FourIs more preferably in the range of 90 to 150 °. Angle θ_FourCan be adjusted to a desired value by appropriately adjusting the positional relationship between the pattern roll 602 and the nip rolls 671 and 672 by changing the height position of the pattern roll 602 or the like. Further, according to the winding method and outer diameter of the polybutylene terephthalate film 601 around the pattern roll 602, the tension applied to the polybutylene terephthalate film 601 by the nip rolls 671 and 672 and the wind pressure applied by the nozzle 603 are appropriately adjusted to obtain a desired value. A linear trace of length and depth is obtained. The tension (tension per width) applied to the film by the nip rolls 671 and 672 is preferably in the range of 0.01 to 5 kgf / cm width.
[0135]
The length and depth of the linear traces are such that the polybutylene terephthalate film 601 travel speed, the pattern roll 602 peripheral speed, the diamond fine particle 604 particle size, so as to satisfy the desired linear tearability length. Adjustment is performed by appropriately setting the outer diameter of the pattern roll, the wind pressure of the nozzle 603, the tension applied by the nip rolls 671 and 672, and the like.
[0136]
(2) When forming diagonal line marks on the film
FIG. 21 is a schematic side view showing an example of an apparatus for forming linear traces oblique to the traveling direction of the polybutylene terephthalate film 601. FIG. The same members or parts as those of the apparatus shown in FIG. 17 are denoted by the same reference numerals. FIG. 21 includes a large number of pattern rolls 621a and 621b installed to be movable in the film width direction as shown in FIG.
[0137]
The pattern rolls 621a and 621b can move linearly along the guide rails 661a and 661b, respectively, so that the roll axis direction is orthogonal to the width direction of the polybutylene terephthalate film 601. In the case of using the apparatus having such a configuration, the axial length of the pattern rolls 621a and 621b and the width of the roll may be about 5 to 10 cm. The gap between the pattern rolls 621a is preferably at least narrower than the width of the pattern roll 621a to increase the density of the pattern roll 621a. The same applies to the pattern roll 621b. As shown in FIG. 22, by providing a large number of pattern rolls 621a and 621b, linear traces are formed in a state where the entire width of the polybutylene terephthalate film 601 on the sliding contact surface is always substantially covered by the pattern roll. As a result, linear traces can be formed densely.
[0138]
The pattern rolls 621a and 621b have a mechanism (not shown) that can move while changing the height position. Examples of such a mechanism include a mechanism in which the support shafts 651a and 651b supporting the pattern rolls 621a and 621b move up and down, a mechanism in which the guide rails 661a and 661b move up and down, and the like. By providing such a mechanism, the pattern rolls 621a and 621b can be repeatedly brought into sliding contact only in a certain direction with a linear movement in a direction perpendicular to the traveling direction of the polybutylene terephthalate film 601, As a result, it is possible to form a certain oblique line mark with respect to the traveling direction of the polybutylene terephthalate film 601.
[0139]
For example, when the pattern rolls 621a and 621b move in the right direction, they slide in contact with the polybutylene terephthalate film 601, and when the pattern rolls 621a and 621b move in the left direction, the height is lowered to move away from the polybutylene terephthalate film 601. The control program may be set so that either one of the pattern rolls 621a and 621b is in contact with the polybutylene terephthalate film 601 almost alternately. Thereby, a fixed linear trace can be formed in the diagonal direction.
[0140]
The angle of the linear traces in the oblique direction with respect to the film traveling direction can be changed by appropriately adjusting the speed at which the pattern rolls 621a and 621b slide and the running speed of the polybutylene terephthalate film 601. Further, the pattern rolls 621a and 621b are rotated in a direction against the progress of the polybutylene terephthalate film 601 on the sliding contact surface with the polybutylene terephthalate film 601. The rotating speed may be approximately the same as the peripheral speed of the pattern roll 602 described in (1) above.
[0141]
FIGS. 23 (a) and 23 (b) show another example of linear trace forming means for forming linear traces oblique to the traveling direction of the polybutylene terephthalate film 601. FIG. FIG. 23 (b) is a view seen from the direction (A) in FIG. 23 (a). In this example, a pattern endless belt 608 to which a large number of pattern rolls 622 are connected is used instead of the method of placing the pattern rolls along the guide rails as shown in FIG. Such a pattern endless belt 608 is slidably contacted with the polybutylene terephthalate film 601 while rotating in a certain direction as shown in FIGS. Diagonal linear marks can be formed. When such a pattern endless belt 608 is used, it is preferable to increase the number of pattern rolls 622 and increase the density of the pattern rolls 622 as much as possible.
[0142]
24 (a) and 24 (b) show another example of linear trace forming means for forming diagonal traces with respect to the traveling direction of the polybutylene terephthalate film 601. FIG. In this example, two pattern rolls 623a and 623b whose length in the axial direction is longer than the width of the polybutylene terephthalate film 601 are installed in parallel in the front-rear direction. As a result, the pattern rolls 623a and 623b can always be brought into sliding contact with the entire width of the polybutylene terephthalate film 601 on the sliding contact surface. The axial length is preferably at least twice the width of the polybutylene terephthalate film 601.
[0143]
The pattern rolls 623a and 623b are installed along the guide rails 662a and 662b so as to be linearly movable in the rotation axis direction. The pattern rolls 623a and 623b include a mechanism (not shown) that can move while changing the height position. By providing such a mechanism, the pattern rolls 623a and 623b can be repeatedly brought into sliding contact in a certain direction with linear movement in the width direction of the polybutylene terephthalate film 601, and as a result, the polybutylene terephthalate film 601 It is possible to form a certain slanted linear trace with respect to the traveling direction. The angle of the linear traces in the oblique direction with respect to the film traveling direction can be changed by appropriately adjusting the speed at which the pattern rolls 623a and 623b are brought into sliding contact with the traveling speed of the polybutylene terephthalate film 601. Reference numerals 652a and 652b denote support shafts for the pattern rolls 623a and 623b, respectively.
[0144]
(3) When forming linear traces in the width direction on the film
FIG. 25 shows an example of a linear trace forming means for forming a linear trace in the width direction on the polybutylene terephthalate film 601. In this example, a pattern endless belt 608a connected to a large number of pattern rolls 624a and a pattern endless belt 608b connected to a large number of pattern rolls 624b are used, so both sides of the center line 609 of the polybutylene terephthalate film 601 are used. It is possible to make sliding contact with the polybutylene terephthalate film 601 while maintaining a predetermined angle with respect to the center line 609.
[0145]
Using the means of such a configuration, the traveling speed of the polybutylene terephthalate film 601, the angle of the pattern endless belts 608a and 608b with respect to the center line 609 of the polybutylene terephthalate film 601, the rotational speed of the pattern endless belts 608a and 608b, etc. In addition, the pattern endless belts 608a and 608b are slidably brought into contact with the polybutylene terephthalate film 601, and the linear traces in the width direction of the polybutylene terephthalate film 601 can be formed. In this case, two nozzles are also provided along the guide rails 663a and 663b (not shown).
[0146]
In the configuration of FIG. 25, it is also possible to form linear traces oblique to the traveling direction of the polybutylene terephthalate film 601 by appropriately changing the setting of the operating conditions.
[0147]
FIG. 26 shows another example of a linear trace forming means for forming linear traces in the width direction of the polybutylene terephthalate film 601. In this example, guide rails 664a and 664b are provided so as to maintain a predetermined angle with respect to the center line 609 of the polybutylene terephthalate film 601, and a large number of pattern rolls 625a and 625b are provided.
[0148]
The pattern rolls 625a and 625b include a mechanism (not shown) that can move while changing the height position thereof. By providing such a mechanism, the pattern rolls 625a and 625b can be repeatedly brought into sliding contact only in a certain direction with linear movement in an oblique direction with respect to the traveling direction of the polybutylene terephthalate film 601. Therefore, by adjusting the sliding speed of the pattern rolls 625a and 625b and the running speed of the polybutylene terephthalate film 601, a certain linear mark can be formed in the width direction of the polybutylene terephthalate film 601. Further, the pattern rolls 625a and 625b are rotated in a direction to resist the progress of the polybutylene terephthalate film 601 on the sliding contact surface with the polybutylene terephthalate film 601. The rotating speed may be approximately the same as the peripheral speed of the pattern roll 602 described in (1) above.
[0149]
FIGS. 27 (a) and (b) show another example of linear trace forming means for forming linear traces in the width direction of the polybutylene terephthalate film 601. FIG. FIG. 27 (b) shows the left side surface of the linear trace forming means (as viewed from the (C) direction in FIG. 27 (a)). In this example, two pattern rolls 626a and 626b having an axial length longer than the width of the polybutylene terephthalate film 601 are provided. As a result, the pattern rolls 626a and 626b can always be brought into sliding contact with the entire width of the polybutylene terephthalate film 601 on the sliding contact surface. The length in the axial direction is preferably at least twice the width of the polybutylene terephthalate film 601. Reference numerals 653a and 653b denote support shafts for the pattern rolls 626a and 626b, respectively.
[0150]
The pattern rolls 626a and 626b are installed so as to be movable along the guide rails 665a and 665b so as to maintain a predetermined angle with respect to the center line 609 of the polybutylene terephthalate film 601. The pattern rolls 626a and 626b have a mechanism (not shown) that can move while changing the height position thereof. The pattern roll 626b is longer than the pattern roll 626a with respect to the axial length. This allows the pattern rolls 626a and 626b to pass each other when traveling in opposite directions.
[0151]
As shown in FIG. 27 (a), the rotation axes of the pattern rolls 626a and 626b maintain a predetermined angle with respect to the center line 609 of the polybutylene terephthalate film 601, and the rotation axes are perpendicular to the rotation axis direction. The pattern rolls 626a and 626b are repeatedly brought into sliding contact with the polybutylene terephthalate film 601 in a predetermined direction so as to move in parallel. In the example of FIG. 27 (a), the pattern rolls 626a and 626b are slidably contacted in a direction against the progress of the polybutylene terephthalate film 601 in the direction orthogonal to the rotation axis direction. The pattern rolls 626a and 626b slidably contacted with the polybutylene terephthalate film 601 by a predetermined distance are opposite to those when the pattern rolls 626a and 626b are separated from the polybutylene terephthalate film 601 by lowering the height as shown in FIG. Return to the direction by a predetermined distance, increase the height again to start sliding contact with the polybutylene terephthalate film 601, and one of the pattern rolls 626a and 626b always slides against the polybutylene terephthalate film 601. The control program may be set as follows.
[0152]
Using such a configuration means, the operating conditions such as the traveling speed of the polybutylene terephthalate film 601, the angle of the rotation axis with respect to the center line 609 of the polybutylene terephthalate film 601, and the speed at which the pattern rolls 626 a and 626 b slide are contacted. After appropriately setting, linear traces in the width direction of the polybutylene terephthalate film 601 can be formed by sliding the pattern rolls 626a and 626b to the polybutylene terephthalate film 601. In this case, as shown in FIG. 27 (b), nozzles 603a and 603b are provided, and the nozzles 603a and 603b are relayed in accordance with the movement of the sliding surface of the pattern rolls 626a and 626b with the polybutylene terephthalate film 601. Try to move it. As a result, air can always be blown against the sliding surface of the pattern roll 626a or 626b with the polybutylene terephthalate film 601.
[0153]
In the configurations of FIGS. 27 (a) and 27 (b), linear traces oblique to the traveling direction of the polybutylene terephthalate film 601 can be formed by appropriately changing the setting of the operating conditions.
[0154]
[5] Ceramic or metal deposition
The polybutylene terephthalate film of the present invention can be vapor-deposited with metal, ceramic or the like, or can be coated with a resin, if necessary. Specific examples of the ceramic to be deposited include silica and alumina. By vapor-depositing ceramic or metal, the gas barrier property of the polybutylene terephthalate film is improved. Vapor deposition of metal, ceramic, etc. can be performed by a known method. When vapor-depositing a metal, ceramic, or the like on a linear easily tearable polybutylene terephthalate film, it may be vapor-deposited on either the linear mark-formed surface or the non-formed surface of the film.
[0155]
[6] Porous
Twistability can be imparted to the polybutylene terephthalate film of the present invention by uniformly forming a large number of fine through holes and / or non-through holes. Micropores have an average opening diameter of 0.5 to 100 μm and a density of about 500 holes / cm²The above is preferable. The density of micropores is about 500 / cm²If it is less than 1, the twist retention is insufficient.
[0156]
In order to form micropores in the polybutylene terephthalate film, for example, methods disclosed in Japanese Patent No. 2071842 and Japanese Patent Application Laid-Open No. 2002-059487 are employed. The method for producing a long porous sealant film disclosed in Japanese Patent No. 2071842 is based on a first roll in which a large number of particles having a Mohs hardness of 5 or more having sharp corners are attached to the surface (the above-mentioned [4] is a linear easy tear The same as pattern roll 602 described for the method for producing a conductive polybutylene terephthalate film) and a second roll having a smooth surface and a long sealant that passes between the rolls. By adjusting the pressing force to the film to be uniform over the entire film surface in contact with each roll, the long sealant film has a diameter of 50 μm or less at the sharp corners of many particles on the surface of the first roll. 500 holes / cm with through or non-through holes²Many are formed with the above density. As the second roll, for example, an iron-based roll, an iron-based roll having a surface plated with Ni, Cr, or the like, a stainless-based roll, a special steel roll, or the like can be used.
[0157]
Porous polybutylene terephthalate film maintains the practical characteristics without losing the heat resistance, fragrance retention, water resistance, etc., which are the excellent characteristics of polybutylene terephthalate film, and has good tearability, twistability and twist retention It is useful as a packaging material comprising When a porous polybutylene terephthalate film is used as a packaging material, it is preferable that the fine holes do not penetrate.
[0158]
[7] Use of shape memory polybutylene terephthalate film laminate
The shape memory polybutylene terephthalate film laminate obtained by the production method described in [3] above is useful as various packaging materials, and is particularly suitable as a packaging material used for lids for instant food containers.
(1) Food container lid
(a) Instant food container lid
When the shape memory polybutylene terephthalate film laminate that stores the curl shape produced by the method described in [3] above is used as a packaging material for the lid of an instant food container, a metal such as an aluminum foil is not used. However, sufficient dead hold property (property that can be maintained with the lid peeled off) can be imparted to the lid. When the shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container, the layer structure shown in FIGS. 12 to 14 described in [3] above is preferable.
[0159]
When manufacturing an instant food container, the shape memory polybutylene terephthalate film laminate is punched out by a lid sealer, and the obtained lid is immediately heat sealed to the container. In heat sealing, the sealing part of the lid body is usually heated to 120 to 160 ° C. by the sealing head of the lid material sealing device. At that time, heat is also applied to parts other than the sealing part of the lid body. T above when sealed₁(Ie T_FiveThe treatment is performed under the above temperature conditions. Therefore, the lid body recovers its curl shape and is flat while being sealed by the container, but exhibits a curl shape by shape memory when peeled from the container. That is, as shown in FIG. 28, when the lid 502 is peeled from the container body 507 to the mark 540 by holding the tab portion 503 of the lid 502, the flap portion formed by opening is held curled and has an aluminum layer. Even if it does not, it has sufficient dead hold property. In particular, when the polybutylene terephthalate film is adhered to the paper sheet in an expanded state while retaining the elastic restoring force as described above, the curling property is further improved. Therefore, hot water can be poured as it is. Such curled lids are used for lids for semi-solid food containers such as jelly and pudding, lids for potion packs such as coffee milk, in addition to lids for instant food containers. It is suitable for.
[0160]
By making the lid body aluminum-free, adverse effects on the environment when incineration can be avoided. If the container main body is also made of aluminum-free material, it is possible to detect a metallic foreign object using a metal detector after sealing the lid. Therefore, not only the safety of instant foods and the like can be further increased, but also the inspection cost can be significantly reduced.
[0161]
When the shape memory polybutylene terephthalate film laminate having a linear easily tearable polybutylene terephthalate film layer described in [4] above is applied to the lid of an instant food container, as shown in FIG. By providing 504 on both sides of the tab portion 503, the lid 502 can be easily partially opened. When the tab portion 503 of the lid 502 is grasped with a finger and pulled to the opposite side of the lid 502, the lid 502 is torn linearly from the cut ends 504 and 504, and an opening 505 is formed in the lid 502. The flap portion 506 formed by tearing has a sufficient dead hold property and is held curled. Accordingly, hot water may be poured into the opening 505 as it is.
[0162]
After pouring hot water, when the flap portion 506 is returned to the original position, there is a jagged break portion 506a (506a, 506a) on one or both outer sides of the flap portion 506. The flap portion 506 cannot be lifted up by engaging with the broken portion of the knurled portion 505a (505a, 505a). In this case, the area of the opening 505 is not only smaller than the conventional full-opening type opening, but also because the flap 506 is locked to the opening 505, even if the container body 507 is accidentally overturned, The amount of hot water leaking is reduced. In FIG. 29, 560 indicates dry noodles.
[0163]
The container body 507 can be formed of a synthetic resin such as paper or styrene foam. In the case of a paper container main body, not only incineration is easy, but there is an advantage that gas that adversely affects the environment is not generated during incineration. In the case of a polystyrene foam container body, there is an advantage that it has excellent heat retention. The shape of the container main body 507 is not limited to the illustrated one, and can be variously changed according to the type of contents.
[0164]
As described in Japanese Patent Application No. 2002-351576, the lid can be provided with slits or slit-like through holes in the tab portion. As a result, when the tab portion is lifted, the lid body can be easily opened in the direction of the other end of the outer peripheral edge, and the flap portion formed by the opening remains substantially curled due to the dead hold property, and the flap portion is returned to the peeling position. After that, it can be resealed by locking the cut or slit-like through hole to the opening edge. The cut or slit-like through hole is formed at a position that does not enter the inside of the seal portion of the lid and can be engaged with the opening edge. Hereinafter, an example in which a cut or slit-like through hole is provided in the tab portion will be described in detail.
[0165]
For example, in the embodiment shown in FIGS. 30 and 31, the tab portion 103 is provided with a slit-like through hole 104 formed in an arc shape substantially along the outer edge of the opening edge portion 111 of the nonmetallic container main body 101. Therefore, as shown in FIG. 32, if the lid 102 is turned and then returned to the original position and the inner edge of the tongue piece 131 is locked to the opening edge 111, the lid 102 cannot be lifted. In FIG. 32, reference numeral 110 denotes a mark indicating the limit of peeling the lid 102 with the tab portion 103.
[0166]
As shown in detail in FIG. 33, the inner edge of the arc-shaped slit-shaped through-hole 104 is located in the sealing portion 102a of the lid (the portion that is heat-sealed by the upper end flange portion 111 of the container body 101), and the outer edge is the opening edge. It is located outside the outer edge of the part 111. Generally, the slit-shaped through hole 104 has an inner edge of the tongue piece portion 131 that is formed by the outer edge of the slit-shaped through hole 104 and the outer edge of the tab portion 103, and the inner edge does not enter the inside of the seal portion 102a. May be provided at a position where it can engage with the opening edge 111. The reason why the inner edge of the slit-like through-hole 104 must be located inside or outside the seal portion 102a of the lid 102 is that the lid 102 is heat sealed to the container body 101 without any gap before opening. Because it must be.
[0167]
Since the tolerance when manufacturing the lid 102 at a high speed by punching a continuous laminated film is about 1 mm, the inner edge of the slit-like through hole 104 is on the outer peripheral side with respect to the center line 102a ′ of the seal portion 102a of the lid 102. Preferably, there is a width D of the seal portion 102a from the outer peripheral side.₁More preferably, it is within the range of 30 to 50%.
[0168]
Slit width d of slit-shaped through-hole 104₁And distance d between both ends₂The outer diameter of the opening edge 111, the opening edge 111 of the opening edge 111 so that the inner edge of the tongue piece 131 formed by the slit-like through hole 104 and the outer edge of the tab 103 can be engaged with the opening edge 111. What is necessary is just to set suitably according to thickness, the magnitude | size of the tab part 103, etc. FIG. For example, in the case of cup noodles poured with hot water, if the outer diameter of the opening edge 111 of the container body 101 is about 10 cm and the thickness of the opening edge 111 is 3 mm, the slit width d₁Is about 1 to 4 mm, and the distance d between both ends₂Is preferably about 3 to 6 cm. Hereinafter, another embodiment of the lid body 102 having different slit-like through holes 104 or cuts 104 will be described later. In any of the examples, the slit width and the distance between both ends of the slit-like through hole 104, and both ends of the cut 104 are provided. The requirements for the spacing d described for Figure 33₁And d₂Is the same.
[0169]
As shown in FIG. 34, the lid 102 may be provided with a pair of cuts 105, 105 on both sides of the tab part 103 as a tear starting point, and the cut part 105 on one side of the tab part 103 as shown in FIG. (Unless otherwise specified, the “cut 105” and the “pair of cuts 105, 105” are collectively referred to as “cut 105”). Thereby, the lid 102 can be easily opened. The cut edge 105 serving as the tear starting point is not particularly limited as long as tearing starts easily, and can be, for example, an I-shaped notch or a V-shaped notch. When providing a pair of cuts 105, 105, the distance D₂Can be appropriately set according to the type of contents. For example, in the case of cup noodles poured with hot water, if the outer diameter of the opening edge 111 of the container body 101 is about 10 cm, the distance D between the cut ends 105, 105₂Is preferably about 4 to 5 cm. In addition, in order to open the entire lid 102 at the time of eating, a second tab portion 132 may be integrally provided on the outer peripheral edge opposite to the tab portion 103 as shown in FIG.
[0170]
FIG. 36 shows another embodiment of the lid body 102 having a cut line or slit-like through hole. In this example, instead of the slit-shaped through hole 104, an arc-shaped cut 104 substantially the same as the outer edge of the opening edge 111 is provided. Since the lid 102 may be the same as the embodiment shown in FIGS. 30 to 33 except for the cut 104, the same reference numerals are given to the same portions as the lid 102 shown in FIGS. If the arcuate cut 104 is inside or outside the seal part 102a of the lid, the inner edge of the tongue piece 131 formed by the arcuate cut 104 and the outer edge of the tab 103 is related to the opening edge 111. It can be provided at a position where it can be combined. Preferably, the position is on the outer peripheral side with respect to the center line 102a 'of the seal portion 102a of the lid 102. When the arc-shaped cut 104 as shown in FIG. 36 is provided, it is preferable to provide circular cuts 141 and 141 for preventing edge cuts at both ends as shown in FIG.
[0171]
FIG. 38 shows still another embodiment of the lid body 102 having a cut line or a slit-like through hole. In this example, the slit-like through hole 104 is formed in an arc shape curved toward the opening edge 111 side. The same reference numerals are assigned to the same parts as those of the lid body 102 shown in FIGS. If the inner end of the arc-shaped slit-shaped through hole 104 curved toward the opening edge 111 is located inside or outside the seal portion 102a, the tongue piece portion formed by this and the outer edge of the tab portion 103 The inner edge portion of 131 may be provided at a position where it can engage with the opening edge portion 111, but it is preferable that both end portions are located on the outer edge of the opening edge portion 111 or on the outer side.
[0172]
FIG. 39 shows still another embodiment of the lid body 102 having a cut line or slit-like through hole. The same reference numerals are assigned to the same parts as those of the lid body 102 shown in FIGS. In this example, the cut 104 is formed in an arc shape curved toward the opening edge 111 side. The position where the curved arc-shaped cut 104 is provided on the opening edge 111 side may be the same as that of the slit-shaped through hole 104 shown in FIG.
[0173]
The cuts 104 and the slit-like through holes 104 described above may be perforated as shown in FIGS. In these cases, the flap portion formed by opening is returned to the peeling position, and the inner edge portion of the tongue piece 131 is pushed downward to cut the perforation, whereby the inner edge portion of the tongue piece 131 is opened. Can be locked to.
[0174]
FIG. 42 shows still another embodiment of the lid body 102 having a cut line or slit-like through hole. In this example, the cut 104 is substantially U-shaped. The same reference numerals are assigned to the same parts as those of the lid body 102 shown in FIGS. The U-shaped cut 104 includes straight portions 142 and 142 and a connecting portion 143 that connects both the straight portions 142 and 142 within the seal portion 102a of the lid, and the straight portions 142 and 142 of the U-shaped cut 104. The tip of is located outside the opening edge 111. In order to secure the seal between the lid 102 and the container body 101, the position where the connecting portion 143 of the U-shaped cut 104 enters the seal portion 102a of the lid is at the center line 102a of the seal portion 102a of the lid It is preferably located on the outer peripheral side with respect to ', and more preferably in the range of 30 to 50% of the width of the seal portion 102a. Two to four U-shaped cuts 104 are preferably formed. Each U-shaped cut 104 is “substantially U-shaped”, and does not have to be exactly U-shaped, but a pair of straight portions and connecting portions like U-shaped or U-shaped. This means that any shape consisting of
[0175]
43 and 44 show still another embodiment of the lid body 102 having a cut line or slit-like through hole. In these examples, the cut 104 is formed in a wave shape. The same reference numerals are assigned to the same parts as those of the lid body 102 shown in FIGS. If the inner end of the corrugated cut 104 is inside or outside the seal portion 102a, the inner edge of the tongue piece 131 formed by this and the outer edge of the tab portion 103 becomes the opening edge 111. It is only necessary to provide it at a position where it can be locked, but it is preferable to provide it so that the corrugated unevenness extends over both the region inside the seal portion 102a of the lid and the region outside the opening edge portion 111. The corrugated shape is not limited to the illustrated shape, and can be appropriately changed. Note that the U-shaped cut 104 and the corrugated cut 104 may be perforated as described above.
[0176]
45 and 46 show another embodiment in which the shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container. This is an example in which a shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container capable of hot water cutting described in Japanese Patent Application No. 2002-264398. In the embodiment shown in FIGS. 45 and 46, the lid body 202 has a substantially circular shape, and a hook-shaped flap portion 203a formed by a tab portion 203 and a pair of cuts 204, 204 provided in the tab portion 203. And have.
[0177]
As shown in detail in FIG. 47, the cuts 204, 204 extend in a substantially L shape from the outer edge of the tab portion 203 to the inside of the seal portion 212 of the lid 202 to form a substantially L-shaped portion 204a. And arc portions 204b extending concentrically with the outer edge of the lid 202 from the front end of the substantially L-shaped portion 204a, and the arc portions 204b and 204b of the cuts 204 and 204 extend in the direction in which the tips 241 and 241 are separated from each other. ing.
[0178]
Both of the arc portions 204b and 204b of the pair of cuts 204 and 204 must be located in the seal portion 212 of the lid 202 (portion that is heat sealed to the upper end flange portion 201a of the container body 201). (I) Before opening, the lid 202 must be heat sealed to the container body 201 without any gaps, and (b) when the lid 202 is peeled off with the hook-shaped flap 203a. This is because other portions including the tongue piece portion 203b of the tab portion 203 must be in close contact with the container body 201 so that only the hook-shaped flap portion 203a and the belt-like flap portion 206 following the flange-shaped flap portion 203a are peeled off.
[0179]
FIG. 48 shows a state in which the lid 202 is opened. Since the lid 202 has the hook-shaped flap portion 203a and the arc portions 204b and 204b of the pair of cuts 204 and 204, they can be easily opened in a band shape. After the hook-shaped flap portion 203a and the subsequent strip-shaped flap portion 206 are peeled off, the tongue pieces 203b and 203b remain in close contact with the upper end flange portion 201a of the container body 201.
[0180]
As shown in FIG. 49, hot water is poured with the lid 202 turned over, and the hook-shaped flap 203a and the band-shaped flap 206 are returned to their original positions, and the hook-shaped flap 203a is engaged with the tongue pieces 203b and 203b. If the outer edge break portions 206a and 206a of the belt-shaped flap portion 206 are engaged with the side edge break portions 205a and 205a of the opening 205, the belt-shaped flap portion 206 cannot be lifted.
[0181]
On the other hand, since the tongue pieces 203b and 203b are not in close contact with the container body 201 unless the arc portions 204b and 204b of the pair of cuts 204 and 204 are located in the seal portion 212 of the lid 202, the positions thereof are changed. It is easy to lock the hook-shaped flap portion 203a to the tongue pieces 203b and 203b.
[0182]
When the lid 202 is manufactured at a high speed by punching a continuous laminated film, the tolerance is about 1 mm. Therefore, the arc portions 204b and 204b of the pair of cuts 204 and 204 are both of the seal portion 212 of the lid 202. The center line 212a is preferably on the outer peripheral side, and more preferably in the range of 30 to 50% of the width D of the seal portion 212 from the outer peripheral side.
[0183]
The distance d between the ends 241 and 241 of the pair of cuts 204 and 204_ThreeCan be appropriately set according to the type of contents. The hook-shaped flap 203a may be of a size sufficient to be picked with a finger and tear the lid 202. At this time, the handle portion 232 of the hook-shaped flap portion 203a may have sufficient strength to peel off the lid 202 with the hook-shaped flap portion 203a, but its minimum width d_FiveIs the distance d between the ends 241 and 241 of the pair of cut ends 204 and 204_ThreeAnd the maximum width d of the umbrella-shaped portion 231 of the hook-shaped flap portion 203a_FourIt is preferable to change appropriately according to. For example, in the case of cup noodles poured with hot water, if the outer diameter of the opening edge 201a of the container body 201 is about 10 cm, the distance d between the tips 241 and 241 of the cut ends 204 and 204 is d._ThreeIs about 4 to 5 cm, and the maximum width d of the umbrella-shaped part 231 of the hook-shaped flap part 203a_FourIs about 2 to 3 cm, and the minimum width d of the handle 232_FiveIs preferably about 1 to 1.5 cm. The shape of the hook-shaped flap portion 203a is not limited to that shown in the figure, and various changes can be made without changing the gist thereof.
[0184]
50 and 51 show another embodiment in which the shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container. This is an example in which a shape memory polybutylene terephthalate film laminate is applied to the lid of an instant food container capable of hot water drainage described in Japanese Patent Application No. 2002-161680. In the embodiment shown in FIGS. 50 and 51, the lid 302 has a substantially circular shape, and the first tab portion 3 and the second tab portion 304 are provided at positions that oppose each other in the diametrical direction. . The first tab portion 303 is for hot water cut opening formation, and the second tab portion 304 is for opening the lid 302.
[0185]
The first tab portion 303 includes a pair of linear cuts 305a and 305b provided near both ends thereof, and a plurality of substantially U-shaped portions formed at equal intervals between the linear cuts 305a and 305b. And a cut 306 having a shape. As shown in detail in FIG. 52, each U-shaped cut 306 is composed of a pair of straight portions 306a, 306a and a connecting portion 306b thereof, and the opening of the U-shaped cut 306 has a lid. Oriented to face the inside of 302. Therefore, the ends of the straight portions 306 a of the pair of straight cuts 305 a and 305 b and the U-shaped cuts 306 are all directed toward the inside of the lid 302. It should be noted that each cut 306 is “substantially U-shaped” and does not need to be exactly U-shaped, but is a shape composed of a pair of linear portions and a connecting portion like a U-shape or U-shape. If so, that means good.
[0186]
As shown in detail in FIG. 52 (a), the ends of the straight portions 306a of the pair of linear cuts 305a, 305b and the U-shaped cuts 306 are both sealed portions 312 (the container body 301 of the container body 301). It must be located within the portion that is heat sealed to the upper end flange portion 301a. (B) Before opening, the lid 302 must be heat-sealed to the container body 301 without any gaps, and (b) it has a first tab portion 303 to form a hot water outlet. This is because when the lid 302 is peeled off, the other portions must be in close contact with the container body 301 so that only the hatched portion 315 is peeled off.
[0187]
FIG. 52 (b) shows a state where the hatched portion 315 is opened. After the hatched portion 315 is peeled off, the strip portion 316 composed of the portion surrounded by the U-shaped cut 306 and its extended portion remains in close contact with the upper end flange portion 301a of the container body 301. On the other hand, if the tip of the straight portion 306a of the pair of linear cuts 305a and 305b and the U-shaped cuts 306 is not located in the seal portion 312 of the lid 302, the first tab portion 303 is provided. When the lid 302 is peeled off, the lid 302 is not torn along the extension lines of the pair of straight cuts 305a and 305b and the straight portions 306a of the U-shaped cuts 306, and the strip 316 is also peeled off. End up.
[0188]
Since the tolerance when manufacturing the lid 302 at a high speed by punching a continuous laminated film is about 1 mm, the tip of the straight portion 306a of each of the pair of linear cuts 305a and 305b and the U-shaped cuts 306 is either In addition, it is preferable that the outer peripheral side with respect to the center line 312a of the seal portion 312 of the lid 302, and the width D of the seal portion 312 from the outer peripheral side._FourMore preferably, it is within the range of 30 to 50%.
[0189]
When the lid 302 is peeled off with the first tab portion 303, the lid 302 is linear along the extension lines of the pair of straight cuts 305a and 305b and the straight portions 306a of the U-shaped cuts 306, respectively. From the viewpoint of tearing the cover 302, the straight cuts 305a and 305b and the direction of the straight part 306a of each U-shaped cut 306 need to substantially coincide with the easy tear direction of the lid 302.
[0190]
The number of U-shaped cuts 306 is appropriately determined depending on the distance between the pair of linear cuts 305a and 305b, the width of the U-shaped cuts 306, etc. 1 to 6 is preferable, and 2 to 5 is more preferable. For example, FIG. 53 shows an example of a lid 302 provided with two accurate U-shaped cuts 306.
[0191]
Distance d between straight cuts 305a and 305b and the closest U-shaped cut₆And the distance d between the U-shaped cuts 306₇Is preferably 3 to 10 mm, and the width d of the U-shaped cut 6₈Is preferably 3 to 10 mm.
[0192]
The lid 302 is preferably provided with a mark 308 indicating the limit of peeling the lid 302 with the first tab portion 303. When the lid 302 is peeled up to the mark 308, a plurality of hot water outlets 318 formed by the lid 302 and the plurality of strip portions 316 are formed. Since the length of the hot water cut opening 318 is determined by the position of the mark 308, the position of the mark 308 is determined so that instant food (yakisoba or the like) in the container can be efficiently cut without leaking. Generally, the length of the hot water cut opening 318 may be 3 to 10 mm.
[0193]
The 2nd tab part 304 is for opening the cover body 302 in order to pour hot water into the instant food in a container. The position of the second tab portion 304 is not limited, but in the case of the circular lid 302 shown in FIGS. 50 and 51, it is preferable that the second tab portion 304 is provided at a position facing the first tab portion 303 in the diameter direction. As shown in FIGS. 50 and 51, the cover 302 may be entirely peeled from the flange portion 301a of the container main body 301 up to the mark 310 provided at an appropriate position of the cover 302, but as shown in FIG. In this way, a partial peeling method may be used. In this case, a pair of cut lines 304a and 304a are provided in the vicinity of both end portions of the second tab portion 304. When the lid 302 is peeled from the container main body 301 with the second tab portion 304, the lid 302 is torn along the extended lines 304b and 304b from the cuts 304a and 304a. If an appropriate mark 310 is provided on the extension lines 304b and 304b, tearing can be stopped there.
[0194]
Further, as the mark 310, a pair of U-shaped cut edges 310 as shown in FIG. 55 may be provided. As a result, when the lid 302 is peeled up to the mark 310, the position where the peeling should be stopped can be easily confirmed, and the lid 302 can be easily bent along the line 310 ′ connecting the pair of marks 310. Can be easily stopped. In addition, there is no limitation in the type | mold of such a pair of cut 310, For example, a V-shaped thing may be used (not shown). Furthermore, a cut may be provided as the mark 310 (not shown).
[0195]
FIG. 56 shows still another embodiment of the lid 302 having a hot water cutout. The same reference numerals are assigned to the same parts as those of the lid 302 shown in FIGS. 51 and 52. In this example, each of the first tab portions 303 is used for forming a hot water cutout, as in the case of the lid 302 shown in FIGS. However, in this example, each first tab portion 303 is torn one by one.
[0196]
Each first tab portion 303 has a pair of linear cuts 305a and 305b provided near both ends thereof. As shown in detail in FIG. 57 (a), the ends of the pair of linear cuts 305a and 305b must be located within the seal portion 312 of the lid 302. Thus, when the lid 302 is torn with each first tab portion 303, only the portion 315 indicated by hatching in the figure can be easily torn as shown in FIG. The portion 316 remains in close contact with the upper end flange portion 301a of the container body 1.
[0197]
The number of the first tab portions 303 is appropriately determined depending on the distance between the pair of straight cuts 305a and 305b, the width of the strip portion 316, etc. -6 are preferable, and 3-5 are more preferable. The first tab portion 303 may be large enough to be picked with a finger and tear the lid 302. The type of the first tab portion 303 is not limited, and examples thereof include a substantially U-shaped one as shown in FIG.
[0198]
FIG. 58 is a perspective view showing another example of a container for instant food provided with a lid having a hot water cutout. The same members or portions as those in the embodiment shown in FIG. 50 are denoted by the same reference numerals. In this example, the lid 302 has a substantially rectangular shape, and the first tab portion 303 and the second tab portion 304 are provided at positions that face each other in a substantially diagonal direction.
[0199]
FIG. 59 shows still another embodiment of the lid 302 having a hot water outlet. The same reference numerals are assigned to the same parts as those of the lid 302 shown in FIGS. 51 and 52. In this example, a first tab portion 303 is provided at substantially the center of one short side of the substantially rectangular lid 302, and the second tab portion 304 is at a position opposite to the other short side. Is provided. The mark 308 is provided on the extension lines 308a and 308a of the straight cuts 305a and 305b, and the lid 302 may be torn to the mark 308 along the extension lines 308a and 308a.
[0200]
FIG. 60 shows still another embodiment of the lid 302 having a hot water outlet. The same reference numerals are assigned to the same parts as those of the lid 302 shown in FIGS. 54 and 59. In this example, a first tab portion 303 is provided at substantially the center of one long side of the substantially rectangular lid 302, and the second tab portion 304 is at a position opposite to the other long side. Is provided.
[0201]
The container shown in FIGS. 50 to 61 has a good sealing property and a hot water draining property, is low in cost, and is particularly useful as a container for yakisoba which needs to be hot watered after pouring hot water. The second tab portion 304 of the container lid shown in FIGS. 50 to 60 may be provided with a cut or slit-like through hole shown in FIGS.
[0202]
As shown in FIG. 61, for example, a plurality of lids are manufactured at a time by punching a laminated sheet 550 made of a shape memory polybutylene terephthalate film laminate. The punching process can be performed using a roll cutter or the like. When the lid 502 is provided with a pair of cuts, the direction of the pair of cuts is the longitudinal direction of the long paper sheet (if the polybutylene terephthalate film has the linear traces described in [4] above, the linear traces Direction) (not shown). In addition, you may perform a punching process with respect to the lamination sheet which piled up many sheets.
[0203]
(b) Semi-solid food container lid
62 and 63 are perspective views showing an example in which the shape memory polybutylene terephthalate film laminate is applied to a lid of a container for containing semi-solid food such as jelly and pudding. When the shape memory polybutylene terephthalate film laminate is applied to the lid of a semi-solid food container, the layer structure shown in FIG. 15 and FIG. 16 described in [3] above is representative. As shown in FIG. 62, in the sealed state, the lid body 502 sealed by the container 507 is flat. However, since the lid 502 has recovered its curl shape when it is heat-sealed to the container 507 (however, it is apparently flat), the shape memory poly having no paper sheet or aluminum foil described with reference to FIGS. The lid 502 made of the butylene terephthalate film laminate is strongly curled by shape memory as shown in FIG. The container body 507 can be formed of a synthetic resin such as polypropylene or polyethylene. The shape of the container main body 507 is not limited to the illustrated one, and can be variously changed according to the type of contents.
[0204]
(c) Heat sealing method
The shape memory polybutylene terephthalate film laminate 450 obtained by the method described in [3] above is apparently substantially flat in the manufacturing process and further stored as a wound film 412. It is almost flat. However, when the shape recovery temperature is relatively low, when storing for a long time, when there is a strong influence of tension when adhering to the film-like molded product described in [3] above, when storing in the hot season in summer, etc. In some cases, the curl shape gradually recovers during storage, or wrinkles that warp on the opposite side of the curl shape due to shape memory may occur due to winding during storage. In particular, in the case of a shape memory polybutylene terephthalate film laminate that does not have a paper layer, an aluminum foil layer, or the like with a strong dead hold property, flatness tends to be lost due to the above factors.
[0205]
The container with a lid is manufactured by punching a shape memory polybutylene terephthalate film laminate obtained by the method described in [3] above and heat-sealing the container. However, the shape memory polybutylene terephthalate film laminate is manufactured. If the container is not substantially flat when unrolled, the container cannot be heat-sealed, or even if it can, it will be a defective product with a bent lid. Therefore, when manufacturing a container with a lid, it is necessary to make the shape memory polybutylene terephthalate film laminate that is not flat when unrolled substantially flat before heat sealing.
[0206]
FIG. 64 is a schematic side view showing an example of an apparatus for producing a container provided with a lid made of a shape memory polybutylene terephthalate film laminate. While the shape memory polybutylene terephthalate film laminate 750 unwound from the wound film 712 obtained by any one of the methods described in [3] above is held flat between the two nip rolls 731, 731 ′, the heater Temperature T exceeding the glass transition temperature of polybutylene terephthalate film by contact with heated air by 732,732_FourIs rapidly annealed and apparently nearly flat. The shape memory polybutylene terephthalate film laminate 750 that has become substantially flat is punched by a lid material sealing device 708 in which a seal head 781 moves up and down and immediately heat-sealed in a container 707. An inert gas can be blown into the container as necessary.
[0207]
However, temperature T_FourIt is necessary to carry out the annealing at such an extent that the curl property stored in the shape memory polybutylene terephthalate film laminate is not lost. Temperature T_FourIs preferably 80 to 120 ° C. Temperature T_FourHeat rapidly until 30-60 seconds. The tension applied to keep flat between the two nip rolls 731 and 731 'is 5 to 10 kgf / m width. The running speed of the normal shape memory polybutylene terephthalate film laminate 750 is 30 to 100 m / min. The temperature of the heaters 732 and 732 is set so that the polybutylene terephthalate film layer of the shape memory polybutylene terephthalate film laminate 750 has a temperature T_FourTo be heated. In FIG. 64, heating is performed from both sides of the shape memory polybutylene terephthalate film laminate 750 by the heaters 732 and 732. Only the heater 732 may be installed. The heated air exiting from the heater 732 may be sprayed onto the polybutylene terephthalate film layer of the shape memory polybutylene terephthalate film laminate 750 using a nozzle.
[0208]
Since the punching of the lid and the heat sealing to the container 707 are performed intermittently, the shape memory polybutylene terephthalate film laminate 750 is not bent between the guide roll 720 and the contact roll 715 as shown in FIG. In addition, a deflection preventing roll 733 is provided for maintaining a constant tension. The deflection preventing roll 733 is movable up and down so as to keep the laminate sheet between the guide roll 720 and the contact roll 715 at a constant tension. In FIG. 64, reference numeral 714 denotes a wound film made of the shape memory polybutylene terephthalate film laminate 750 after the cover is punched out.
[0209]
In heat sealing, the sealing part of the lid is normally heated to 120 to 160 ° C. by the seal head 781, and at that time, heat is also applied to parts other than the sealing part of the lid, so that the lid is heat sealed to the container. The curl shape is recovered and is flat while being sealed to the container, but shows a curl shape by shape memory by peeling from the container.
[0210]
(2) Tray for food
The shape memory polybutylene terephthalate film laminate obtained by the example shown in FIG. 11 described in the above [3] (1) (c) is cut for each tray shape unit length while being flat. Can be used as a tray. For example, as shown in FIG. 65, after the instant frozen food 35 or the like is placed on the obtained food tray 534, it is packaged with a packaging film 536 to form a packaged product 537. As shown in FIG. 65, the packaged product 537 is heated by a microwave oven 538 or the like to eat, but at this time the temperature T₁By performing the heat treatment at the above temperature, the food tray 534 develops the tray shape formed by the pressing die 430. In this way, when the shape memory polybutylene terephthalate film laminate is applied to the food tray 534, it is almost flat in the state of the packaged product 537, so the volume is small, convenient for transportation and display, and the tray shape is changed by heat treatment. There is a convenience that can be expressed and easy to eat.
[0211]
The packaging film 536 for packaging the food tray 534 has a large number of substantially parallel linear traces on at least one surface by the method disclosed in Japanese Patent Application No. 2002-125045 described in [4] above. Is preferably formed. Thereby, the packaging film 535 has linear tearability in one direction regardless of the orientation, and can be linearly split along a linear mark from any part. Therefore, the packaging film 535 can be easily partially opened when eating. Since the linear trace formed by the method disclosed in Japanese Patent Application No. 2002-125045 does not penetrate the film, the packaging film 535 has excellent gas barrier properties even after the linear trace is formed.
[0212]
As mentioned above, although this invention was demonstrated with reference to drawings, this invention is not limited to them, A various change can be added unless the meaning of this invention is changed.
[0213]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
[0214]
Example 1
A polybutylene terephthalate film was produced by an air-cooled inflation molding method using the apparatus shown in FIG. Polybutylene terephthalate resin (trade name “Trecon 1209X01”, manufactured by Toray Industries, Inc.) was put into a twin-screw extruder (screw diameter 50 mm, extrusion rate 50 kg / hr), melt-kneaded at 235 ± 5 ° C., A molten resin was prepared in an extruder. Subsequently, this molten resin is extruded from an annular die (die diameter 150mmφ) installed at the tip of the extruder at a blow-up ratio of 2.5 (extrusion resin pressure: 120kg / cm²), (1) The bubble neck is cooled to 185 ° C by blowing hot air (30 ° C) from the first hot air blowing device, and (2) the temperature is discharged from the second hot air blowing device. By blowing wind air (30 ° C), the expanded part of the bubble is cooled down to 160 ° C. (3) By blowing warm air (50 ° C) from the third warm air blowing device, the frost line is 125 (4) The upper bubble region is surrounded by a cylindrical fiber (material: nylon) and the outer bubble region is surrounded by an acrylic resin partition wall and a bar heater is provided on the inner surface side of the partition wall. Was held at 100 ° C. to obtain a film having an average film thickness of 20 μm. The average film thickness is an average value of values obtained by measuring a total of 6 film thicknesses by using a contact thickness meter with respect to the thickness of the center and both ends of the sheet in the width direction. The obtained polybutylene terephthalate film was measured for film thickness difference and heat shrinkage rate (refer to [2] above for the method of measuring film thickness difference and heat shrinkage rate, the same shall apply hereinafter). As a result, the film thickness difference was 3 μm, and the thermal shrinkage rates were MD 0.1% and TD 0.15%.
[0215]
Example 2
A polybutylene terephthalate film was produced by simultaneous biaxial stretching using the apparatus shown in FIG. Polybutylene terephthalate resin (trade name “Trecon 1200S” manufactured by Toray Industries, Inc.) was put into a twin screw extruder (screw diameter 50 mm, extrusion rate 50 kg / hr), melt kneaded at 235 ± 5 ° C., A molten resin was prepared in an extruder. Subsequently, this molten resin was extruded from a T-die installed at the tip of the extruder, cooled while being pulled by a heating casting roll (circumferential speed 10 m / min) adjusted to 180 ° C., and an amorphous film having an average film thickness of 50 μm. A quality sheet was formed. Subsequently, the obtained amorphous sheet was stretched twice in the machine direction and twice in the transverse direction at 180 ° C. with a simultaneous biaxial stretching apparatus (see FIG. 6), and then rapidly cooled with cooling air to obtain an average film. A polybutylene terephthalate film having a thickness of 13 μm was prepared. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 2 μm, and the heat shrinkage rates were MD0.15% and TD0.2%.
[0216]
Example 3
Using the apparatus shown in FIG. 5, air-cooled inflation molding, tubular inflation PBT film cutting and cold drawing were continuously performed in-line to produce a polybutylene terephthalate film. Air-cooled inflation molding was performed in the same manner as in Example 1 to obtain an inflation film having an average film thickness of 25 μm. Then, it adjusted to the fixed edge position by the edge position control apparatus, and it was torn with the cutter horizontally with respect to the sheet | seat surface from the both ends folding part. Subsequently, each of the two blown PBT films divided into two was driven in parallel with two slow drive rolls (peripheral speed 18 m / min, see FIG. 5) each adjusted to 65 ° C., and 15 ° C. respectively. The film was cold-drawn twice as much as MD between two continuous high-speed rolls (circumferential speed 36 m / min, see FIG. 5). Subsequently, it heat-processed with the heater at 80 degreeC, and produced the polybutylene terephthalate film with an average film thickness of 12 micrometers. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 1.5 μm, and the heat shrinkage rates were MD 0.1% and TD 0.15%.
[0217]
Example 4
A polybutylene terephthalate film having an average film thickness of 6 μm was prepared in the same manner as in Example 3 except that an inflation film having an average film thickness of 20 μm was prepared and cold-drawn 4 times to MD. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 1.5 μm, and the heat shrinkage rates were MD 0.1% and TD 0.1%.
[0218]
Example 5
A polybutylene terephthalate film having an average film thickness of 3 μm was prepared in the same manner as in Example 3 except that an inflation film having an average film thickness of 20 μm was prepared and cold-stretched 6 times to MD. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 1 μm, and the heat shrinkage rates were MD 0.1% and TD 0.1%.
[0219]
Example 6
The inflation film produced in Example 1 was further cold-drawn twice at TD at 65 ° C. to obtain a film having an average film thickness of 10 μm. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 2 μm, and the heat shrinkage rates were MD 0.1% and TD 0.15%. About the obtained polybutylene terephthalate film, the surface was observed by AFM. FIG. 66 shows a diagram of the obtained AFM image. From FIG. 66, it can be seen that the polybutylene terephthalate film has linear wrinkles, the height difference of the concavo-convex structure is 200 to 300 nm, and the width of the concavo-convex structure is 3000 to 20000 nm.
[0220]
Example 7
The inflation film produced in Example 1 was further cold-drawn twice in MD at 65 ° C. to obtain a film having an average film thickness of 10 μm. When the film thickness difference and heat shrinkage rate of the obtained polybutylene terephthalate film were measured, the film thickness difference was 2 μm, and the heat shrinkage rates were MD 0.1% and TD 0.15%. About the obtained polybutylene terephthalate film, the surface was observed by AFM. A diagram of the obtained AFM image is shown in FIG. From FIG. 67, it can be seen that the polybutylene terephthalate film has linear wrinkles, the height difference of the uneven structure is 90 to 100 nm, and the width of the uneven structure is 500 to 2000 nm.
[0221]
Example 8
In the same manner as in Example 6, two cold-stretched films were produced, and a laminated body was produced so that the directions of the linear wrinkles were almost perpendicular to each other, and the light of the flashlight passed through this was photographed with a camera. The results are shown in FIG. From FIG. 68, it can be seen that the light seen through the laminated body appears to have two light streaks having substantially the same width as the light source substantially orthogonal to each other with the light source as the center.
[0222]
Example 9
In the same manner as in Example 6, four cold-stretched films were produced, and a laminated body was produced so that the direction of the linear wrinkles was rotated by about 45 °, and the light from the flashlight passed therethrough was photographed. Taken with The results are shown in FIG. From FIG. 69, it can be seen that the light seen through the laminated body appears to have three light streaks having substantially the same width as the light source at an angle of approximately 45 degrees with respect to the light source.
[0223]
The polybutylene terephthalate films of Examples 1 and 2 manufactured by the method of the present invention are stretched in the biaxial direction at the same time in an amorphous state, so that it is understood that the film thickness is excellent and the thermal shrinkage rate is low. . Since the polybutylene terephthalate films of Examples 3 to 7 are further cold-drawn from the inflation film produced by the air-cooled inflation molding method of the present invention, the thickness uniformity is further improved. The polybutylene terephthalate films of Examples 8 and 9 have an infinite number of fine line wrinkles extending in the machine direction or the transverse direction, and thus have an effect of diffracting / scattering light.
[0224]
【The invention's effect】
As described above in detail, since the method for producing a polybutylene terephthalate film by the air-cooled inflation molding method of the present invention expands while maintaining bubbles in an amorphous state, the film thickness uniformity and heat shrinkage are thin. A polybutylene terephthalate film excellent in rate can be produced.
[0225]
In the method for producing a polybutylene terephthalate film by the simultaneous biaxial stretching method of the present invention, an amorphous sheet is formed by removing the molten polybutylene terephthalate resin extruded from a die on a heating casting roll, which is then amorphous. Since it is simultaneously biaxially stretched while maintaining the quality state, it is possible to produce a polybutylene terephthalate film that is thin but excellent in film thickness uniformity and thermal shrinkage.
[0226]
In the polybutylene terephthalate film manufacturing apparatus of the present invention, the inflation molding part, the edge position control device, the cutting means, and the cold drawing means have an in-line configuration, so that (1) air-cooled inflation molding, (2) tube It is possible to improve the efficiency of a series of steps consisting of cutting of the shaped inflation PBT film and (3) cold drawing.
[0227]
As described in detail above, the polybutylene terephthalate film of the present invention not only has excellent film thickness uniformity and heat shrinkage, but also has excellent shape memory, so it can be used for various packaging materials, packaging bags, and instant foods. Suitable for applications such as container lids.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an example of an apparatus for producing a polybutylene terephthalate film by the air-cooled inflation molding method of the present invention.
FIG. 2 is a schematic side view showing an example of an apparatus for removing and cooling bubbles.
FIG. 3 is a schematic side view ((a)) and a schematic plan view ((b)) showing an example of an apparatus for successively biaxially cold-drawing a polybutylene terephthalate film produced by an air-cooled inflation molding method.
FIG. 4 is a schematic side view showing various examples of an apparatus for cold-drawing a polybutylene terephthalate film produced by an air-cooled inflation molding method in the machine direction.
FIG. 5 is a schematic side view showing an example of an apparatus for cold-drawing a polybutylene terephthalate film produced by an air-cooled inflation molding method by an in-line method.
FIG. 6 is a schematic plan view showing an example of an apparatus for producing a polybutylene terephthalate film by the simultaneous biaxial stretching method of the present invention.
FIG. 7 is a schematic side view showing an example of an apparatus for producing a shape memory polybutylene terephthalate film laminate.
FIG. 8 is a schematic side view showing another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate.
FIG. 9 is a schematic side view showing still another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate.
FIG. 10 is a schematic side view showing still another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate.
FIG. 11 is a schematic side view showing still another example of an apparatus for producing a shape memory polybutylene terephthalate film laminate.
FIG. 12 is a cross-sectional view showing a first layer configuration example of a shape memory polybutylene terephthalate film laminate.
FIG. 13 is a cross-sectional view showing a second layer configuration example of a shape memory polybutylene terephthalate film laminate.
FIG. 14 is a cross-sectional view showing a third layer configuration example of a shape memory polybutylene terephthalate film laminate.
FIG. 15 is a cross-sectional view showing a fourth layer configuration example of a shape memory polybutylene terephthalate film laminate.
FIG. 16 is a cross-sectional view showing a fifth layer configuration example of the shape memory polybutylene terephthalate film laminate.
FIG. 17 is a schematic side view showing an example of an apparatus for forming linear marks in the traveling direction of a polybutylene terephthalate film.
18 is a partially enlarged plan view showing a state in which compressed air is blown onto the surface of the film in sliding contact with the pattern roll in the apparatus shown in FIG.
19 is a partial enlarged cross-sectional view showing a state in which a film is in sliding contact with a pattern roll in the apparatus shown in FIG.
20A is a front view and a right side view showing an example of a nozzle, FIG. 20B is a front view and a right side view showing another example of the nozzle, and FIG. 20C is a nozzle having a hood. It is a schematic side view which shows a mode that a compressed roll is sprayed on a pattern roll using, and shows the example of how to wind the film around a pattern roll.
FIG. 21 is a schematic side view showing an example of an apparatus for forming linear traces oblique to the traveling direction of a polybutylene terephthalate film.
22 is a partially enlarged plan view showing how the pattern roll operates in the apparatus shown in FIG. 21. FIG.
FIG. 23 (a) is a partially enlarged plan view showing another example of an apparatus for forming linear traces oblique to the traveling direction of the polybutylene terephthalate film, and FIG. 23 (b) is a plan view of (a). It is the schematic side view seen from the (A) direction in the figure.
FIG. 24 (a) is a partially enlarged plan view showing another example of an apparatus for forming linear traces oblique to the traveling direction of the polybutylene terephthalate film, and FIG. 24 (b) is a plan view of (a). It is the schematic side view seen from the (B) direction in the figure.
FIG. 25 is a partially enlarged plan view showing an example of an apparatus for forming linear traces in the width direction with respect to the traveling direction of the polybutylene terephthalate film.
FIG. 26 is a partially enlarged plan view showing another example of an apparatus for forming linear marks in the width direction with respect to the traveling direction of the polybutylene terephthalate film.
FIG. 27 (a) is a partially enlarged plan view showing another example of an apparatus for forming linear traces in the width direction with respect to the traveling direction of the polybutylene terephthalate film, and FIG. It is the schematic side view seen from the (C) direction in the figure.
FIG. 28 is a perspective view showing an instant food container in which a lid made of a shape memory polybutylene terephthalate film laminate is opened for pouring hot water.
FIG. 29 is a perspective view showing an instant food container in which a lid made of a shape memory polybutylene terephthalate film laminate is partially opened for pouring hot water.
FIG. 30 is a perspective view showing an example of an instant food container provided with a lid made of a shape memory polybutylene terephthalate film laminate.
31 is a plan view showing the instant food container of FIG. 30. FIG.
32 is a perspective view showing a state where the instant food container of FIG. 30 is opened and resealed. FIG.
33 is a partially enlarged view showing the vicinity of the tab portion of the lid body of FIG. 31. FIG.
FIG. 34 is a plan view showing another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 35 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 36 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 37 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 38 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 39 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 40 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 41 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 42 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 43 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 44 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 45 is a perspective view showing another example of an instant food container provided with a lid made of a shape memory polybutylene terephthalate film laminate.
46 is a plan view showing the instant food container of FIG. 45. FIG.
47 is a partially enlarged view showing the vicinity of the tab portion of the lid body of FIG. 45. FIG.
48 is a perspective view showing a state in which the instant food container shown in FIG. 45 is opened. FIG.
49 is a perspective view showing a state in which the instant food container of FIG. 45 is re-sealed after opening. FIG.
FIG. 50 is a plan view showing still another example of an instant food container provided with a lid made of a shape memory polybutylene terephthalate film laminate.
51 is a plan view showing the instant food container of FIG. 50. FIG.
52 is a partially enlarged view showing the vicinity of the first tab portion of the lid of FIG. 50, (a) showing a state where the lid near the first tab is not turned, and (b) showing the first tab portion. The state which turned the cover body of one tab part vicinity is shown.
FIG. 53 is a partially enlarged view showing the vicinity of a first tab portion of still another example of a lid body made of a shape memory polybutylene terephthalate film laminate.
FIG. 54 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 55 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 56 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
57 is a partially enlarged view showing the vicinity of the first tab portion of the lid of FIG. 56, (a) showing a state where the lid near the first tab is not turned, and (b) showing the first tab portion. The state which turned the cover body of one tab part vicinity is shown.
FIG. 58 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 59 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 60 is a plan view showing still another example of a lid made of a shape memory polybutylene terephthalate film laminate.
FIG. 61 is a plan view showing a state in which a plurality of lids are punched from a shape memory polybutylene terephthalate film laminate.
FIG. 62 is a perspective view showing an example of a semi-solid food container provided with a lid made of a shape memory polybutylene terephthalate film laminate.
63 is a perspective view showing a state where the semi-solid food container of FIG. 26 is opened. FIG.
FIG. 64 is a schematic side view showing an example of an apparatus for producing a container with a lid.
FIG. 65 is a schematic side view showing the shape recovery of the shape memory polybutylene terephthalate film laminate used for the food tray.
66 is a graph showing an AFM image of the polybutylene terephthalate film of Example 3. FIG.
67 is a graph showing an AFM image of the polybutylene terephthalate film of Example 4. FIG.
68 is a photograph of light viewed through the laminated cold-drawn film of Example 5. FIG.
FIG. 69 is a photograph of light viewed through the laminated cold-drawn film of Example 6.
[Explanation of symbols]
1 ... Annular die
11 ... Annular orifice
12 ... Extruder
13 ... Tipper nip roll
14 ... take-up reel
15 ... Insulation
16 ... Guide roll
17 ... Nip roll
18 ... Cutter
19 ... Heater
2,2 '... Inflation PBT film
20 ... First hot air blowing device
21 ... Second warm air blowing device
22 ・ ・ ・ Third warm air blowing device
23 ... Bulkhead
24 ・ ・ ・ Heating means
25 ・ ・ ・ Cylindrical fiber
26 ... Air injection pipe
27 ... Cooling tower
3 ... Bubble
31 ... Neck
32 ... Expanded part
33 ・ ・ ・ Bubble area
34 ... Frost line
4 ... Machine direction stretching part
41 ・ ・ ・ Slow drive roll
42 ... High-speed drive roll
43 ... Heating roll (preheating roll)
44 ・ ・ ・ Cooling roll
45 ・ ・ ・ Heating slow drive roll
46 ... Cooling speed drive roll
5 ... Tenter (transverse section)
51 ・ ・ ・ Film clip roller
52 ... Gear
53 ・ ・ ・ Hot air introduction hole
54 ... food
6 ... Amorphous sheet
60 ・ ・ ・ Die for sheet
61 ・ ・ ・ Heating casting roll
63 ... stretched film
7 ... Simultaneous biaxial stretching equipment
71 ... Film clip roller
72 ・ ・ ・ Gear
73 ・ ・ ・ Chain
74 ・ ・ ・ Slow drive rubber roll
75 ・ ・ ・ Speed-driven rubber roll
8. Edge / position control device
81 ... Guide roll
82 ・ ・ ・ Connection shaft
83 ・ ・ ・ Sensor
101 ・ ・ ・ Non-metal container body
111 ・ ・ ・ Open edge (upper flange)
102 ... lid
102a ・ ・ ・ Seal part
102a ’・ ・ ・ Center line of seal
103 ... Tab part
131 ・ ・ ・ Tongue
104 ... Slit-shaped through hole (cut)
141 ... notches
142 ・ ・ ・ Linear part of U-shaped cut
143 ... Connection part of U-shaped cut
105 ... Tearning start point (cut)
105 '・ ・ ・ Extension line of tear start point
106 ・ ・ ・ Flap part
201 ・ ・ ・ Container body
201a ・ ・ ・ Upper flange part
202 ... lid
212 ・ ・ ・ Seal part
212a ・ ・ ・ Center line of seal part
203 ・ ・ ・ Tab
203a ・ ・ ・ Strap-shaped flap
231 ・ ・ ・ Umbrella-shaped part of the hook-shaped flap
232 ... Patterned part of bowl-shaped flap
203b ・ ・ ・ Tongue piece
204 ... cut
204a ・ ・ ・ Abbreviated L-shaped part of cut
204b ・ ・ ・ Arc portion of the cut
241 ... Cut tip
204 ’・ ・ ・ Extension line
205 ... Opening
205a ... Jagged fracture surface of paper sheet layer
206 ・ ・ ・ Strip flap
206a ・ ・ ・ Jagged fracture surface of paper sheet layer
230 ... Dried noodles
301 ... Container body
301a ・ ・ ・ Upper flange
302 ... Lid
312 ・ ・ ・ Seal part
312a ・ ・ ・ Center line of seal part
303 ・ ・ ・ First tab
304 ・ ・ ・ Second tab
304a ・ ・ ・ Cut
304b ・ ・ ・ Extension line
305a, 305b ・ ・ ・ Linear cut
306 ・ ・ ・ U-shaped cut
306a ・ ・ ・ Linear part
306b ・ ・ ・ Connecting part
308 ... mark
308a ・ ・ ・ Extension line of cut
310, 310 ’... mark
315 ・ ・ ・ Peeling part near the first tab (hatched part)
316 ・ ・ ・ Strip part
318 ... hot water outlet
401 ・ ・ ・ Polybutylene terephthalate film
410 ... Original film
411 ... Curl laminate
412 ... Rolled film
413 ... Film-like molded body
414 ... Laminate
415 ... Deformed laminate
416 ... Coating film
420 ・ ・ ・ Guide roll
421 ... gravure roll
422 ... Die
423 ... Drying furnace
424 ... Pressure adjustment roll
425 ... Cooling roll
425 ’・ ・ ・ Rubber roll
426 ・ ・ ・ Cold processing roll
427, 427 '... Nip roll
428 ... Cooling roll
429 ... Heater
430 ...
431 ・ ・ ・ Annealing roll
432 ... Cooling device
433 ・ ・ ・ Take-up roll
438 ... Heating roll
502: Lid
503 ... Tab part
507 ... Non-metal container body
571 ・ ・ ・ Open edge (upper flange)
502a ・ ・ ・ Seal part
504 ... Tearning start point (cut)
505 ... Opening
505a, 506a ... Jagged fracture surface of paper sheet layer
506 ・ ・ ・ Flap part
534 ・ ・ ・ Food tray
535 ... Instant frozen food
536 ・ ・ ・ Packaging film
537 ・ ・ ・ Packed products
538-Microwave oven
540 ... mark
550 ... Shape memory polybutylene terephthalate film laminate
551 ・ ・ ・ Polybutylene terephthalate film layer
552 ... paper sheet
553 ... Light-shielding ink layer
554 ・ ・ ・ Sealant film layer
555 ... Polyethylene (layer) (I)
555 '... polyethylene (layer) (II)
555 "... polyethylene (layer) (III)
556 ・ ・ ・ Adhesive (layer) (I)
556 '・ ・ ・ Adhesive (layer) (II)
556 ″… Adhesive (layer) (III)
557 ... PET layer
560 ・ ・ ・ Dried noodles
601 ... Film
602, 621a, 621b, 622, 623a, 623b, 624a, 624b, 625a, 625b, 626a, 626b, ... pattern roll
603, 603a, 603b ... Blower
631 ・ ・ ・ Outlet
632 ... Food
604 ・ ・ ・ Diamond fine particles
651a, 651b, 652a, 652b, 653a, 653b ... Pattern roll support
661a, 661b, 662a, 662b, 663a, 663b, 664a, 664b, 665a, 665b ... guide rail
607 ・ ・ ・ Original film
671,672 ... Nip roll
673,674 ・ ・ ・ Guide roll
675 ・ ・ ・ Rewind reel
608, 608a, 608b ... Pattern endless belt
609 ・ ・ ・ Center line of film
712 ... Rolled film
714 ... Wound film made of PBT film laminate after punching
750 ... Shape memory polybutylene terephthalate film laminate
731,731 '・ ・ ・ Nip roll
732 ... Heater
733 ・ ・ ・ Bending prevention roll
708 ... Lid sealing device
707 ・ ・ ・ Non-metal container body
781 ・ ・ ・ Seal head
715 ... Contact roll

Claims (15)

Bubbles are formed by injecting air into molten polybutylene terephthalate resin extruded into a tube shape from an annular die, and the bubbles are expanded by internal pressure and formed into a tubular film by air cooling. A method for producing a polybutylene terephthalate film, which includes an air-cooled inflation molding process in which a film-like film is folded into a sheet while being folded by a pair of nip rolls,
(1) By discharging hot air from a first hot air blowing device provided in the vicinity of the annular die, the bubble neck is cooled to 180 ° C. or more and 195 ° C. or less,
(2) By blowing hot air from a second hot air blowing device provided at the top of the first hot air blowing device, the bubbles are further cooled to 150 ° C. or higher and 180 ° C. or lower, Thus, the bubbles are expanded while being held in an amorphous state,
(3) The bubble frost line is cooled to 90 ° C. or higher and 130 ° C. or lower by blowing hot air from a third hot air blowing device provided at the upper part of the second hot air blowing device. And
(4) The upper bubble area above the frost line is blocked from the external atmosphere, and the warm air blown from each of the first to third warm air blowing devices is blown up along the outer surface of the upper bubble area. The partition wall for enclosing the upper bubble region and providing a heating means on the inner surface side of the partition wall, so that the upper bubble region is maintained above the glass transition temperature of the polybutylene terephthalate resin to below the glass transition temperature + 65 ° C. A method for producing a polybutylene terephthalate film, comprising: The method for producing a polybutylene terephthalate film according to claim 1, wherein the blow-up ratio is 2.0 to 4.5. The method for producing a polybutylene terephthalate film according to claim 1 or 2, wherein the bubble is prevented from rolling by surrounding the upper bubble region with a cylindrical fiber. Production method. In the manufacturing method of the polybutylene terephthalate film in any one of Claims 1-3, the temperature of the warm air blown from said 1st and 2nd warm wind air blowing apparatus is 25-50 degreeC, Said 3rd The method for producing a polybutylene terephthalate film, characterized in that the temperature of the warm air blown from the hot air blowing device is above the glass transition temperature of the polybutylene terephthalate resin to not more than the glass transition temperature + 65 ° C. 5. The method for producing a polybutylene terephthalate film according to claim 1, wherein the polybutylene terephthalate resin further has a glass transition temperature higher than the glass transition temperature and not higher than 60 ° C., and is 2 in the machine direction or the lateral direction. A method for producing a polybutylene terephthalate film, characterized in that the film is uniaxially cold-drawn at least twice or successively biaxially cold-drawn at a surface magnification of 2 times or more in the machine direction and the transverse direction. In the manufacturing method of the polybutylene terephthalate film according to claim 5,
(1) formation of the tubular film, and
(2) A method for producing a polybutylene terephthalate film, wherein the uniaxial cold stretching or the sequential biaxial cold stretching is continuously performed by an in-line method. 6. The method for producing a polybutylene terephthalate film according to claim 5, wherein the sheet-like tubular film taken up by the nip roll is divided into two in advance before the uniaxial cold drawing or sequential biaxial cold drawing. A method for producing a polybutylene terephthalate film. In the manufacturing method of the polybutylene terephthalate film according to claim 7,
(1) Formation of the tubular film,
(2) the tubular film is divided into two parts, and
(3) A method for producing a polybutylene terephthalate film, wherein the uniaxial cold stretching or the sequential biaxial cold stretching is continuously performed by an in-line method. In the method for producing a polybutylene terephthalate film in which a polybutylene terephthalate resin is formed into a film by a stretching method, the molten polybutylene terephthalate resin is extruded from a die and is cooled to 180 ° C. to 195 ° C. on a heating casting roll. A polybutylene terephthalate film formed by forming an amorphous sheet, biaxially stretching the resulting amorphous sheet while maintaining the amorphous state at 150 ° C. to 180 ° C., and then rapidly cooling the amorphous sheet. Manufacturing method. A polybutylene terephthalate film obtained by the production method according to claim 5, which is not easily tearable in any direction, and is cooled by the uniaxial cold stretching or the sequential biaxial cold stretching. A polybutylene terephthalate film having a heat shrinkage in the stretched direction of 1% or less. A polybutylene terephthalate film obtained by the manufacturing method according to claim 5, wherein the polybutylene terephthalate film has countless linear wrinkles extending in a machine direction or a transverse direction. Terephthalate film. 12. The polybutylene terephthalate film according to claim 11, wherein the uneven structure formed by the linear wrinkles has a height difference of 50 to 500 nm, and the width of the uneven structure is 500 to 20000 nm. Terephthalate film. (a) an extruder for heating and melting the polybutylene terephthalate resin and feeding it; (b) an annular die connected to the downstream end of the extruder for extruding the molten polybutylene terephthalate resin into a tube; (c) air injection means for forming air bubbles by injecting air into the molten polybutylene terephthalate resin extruded in a tube shape from the annular die, and (d) air cooling means for air cooling the bubbles, e) A polybutylene terephthalate film manufacturing apparatus including at least an inflation molding apparatus having a pair of nip rolls for taking up a tubular film obtained by air cooling the bubble, wherein the air cooling means includes:
(1) a first hot air blowing device provided near the annular die for cooling the neck of the bubble;
(2) a second hot air blowing device provided at an upper portion of the first hot air blowing device for further cooling the bubble so that the bubble expands in an amorphous state;
(3) a third hot air blowing device provided at the upper part of the second hot air blowing device for removing the frost line of the bubble;
(4) provided above the third warm air blowing device and around the upper bubble region above the frost line, shuts off the upper bubble region from the external atmosphere, and A partition for blowing hot air blown from each of the wind air blowing devices along the outer surface of the upper bubble region,
(5) heating means provided on the inner surface side of the partition;
(6) A polybutylene terephthalate film, characterized in that it is provided so as to surround the inner surface side of the partition wall and the vicinity of the upper bubble region, and has a cylindrical fiber for preventing rolling of the bubble. Manufacturing equipment. 14. The apparatus for producing a polybutylene terephthalate film according to claim 13, further comprising cold drawing means for cold drawing in the machine direction and / or the transverse direction, and the inflation molding section and the cold drawing means are in-line configuration. An apparatus for producing a polybutylene terephthalate film, wherein In the apparatus for producing a polybutylene terephthalate film according to claim 14, between the inflation molding portion and the cold stretching means,
(1) an edge position control device for controlling the edge position of the sheet-like tubular film taken up by the nip roll to be constant;
(2) further comprising a cutting means for splitting the tubular film whose ear end position is controlled to be constant, and thus the inflation molding section, the edge position control device, and the cutting means. The apparatus for producing a polybutylene terephthalate film is characterized in that the cold stretching means has an in-line configuration.

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