JPH0757813B2 - Method for manufacturing polyester tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tubular body using a polyester film (including a sheet, the same applies hereinafter) as a material, and more specifically, a container, a bottle (including a plastic bottle), a can, a rod. For coating objects (pipes, rods, wood, various rod-shaped objects), etc. (hereinafter abbreviated as containers),
In particular, the present invention relates to a method for producing a tubular material which is used for the purpose of marking, protection, bundling, improving the commercial value, etc. by covering a part or the whole surface of these caps, shoulders, trunks and the like.

[0002]

2. Description of the Related Art Conventionally, a film made of polyvinyl chloride, polystyrene, polyethylene, hydrochloric acid rubber or the like has been used for the above-mentioned uses, and this was made into a tubular body and then covered with the above containers to be heat-shrinked.

In the case of producing a tubular body using polyvinyl chloride or polystyrene, a solvent is often applied to the film for bonding, and an ultrasonic seal may be used in some cases. When polyethylene is used as the material, a fusing seal method or an impulse seal method is also used.

[0004]

However, these conventional techniques have the following problems. (a) Industrial waste problem In recent years, the amount of plastic bottles used has increased rapidly. Considering the recovery of this bottle, there is a problem that it cannot be recovered and reused, especially when a different film such as vinyl chloride or polystyrene is used for coating the polyester bottle. In addition, when incinerated, high heat is generated to adversely affect the treatment equipment, and there is a problem of corrosion due to chlorine gas.

(B) Insufficient heat resistance All of the above conventional films cannot withstand high temperature boil treatment or retort treatment, and are unsuitable for sterilization treatment. For example, when the retort treatment is performed, the conventional film is destroyed and burst during the treatment, and all the functions are lost.

(C) Printability Regarding the generation of pinholes due to halftone printing and the adhesion to various inks over a wide range, the above conventional films have their own drawbacks. For example, in the case of vinyl chloride, ink pinholes due to gels are likely to occur, and in continuous tube processing, if there are pinholes in the middle of a long film, when these are supplied to an automatic labeling machine, they will still have pinholes. Since it is commercialized, it is necessary to finally inspect all products, and the labor and reworking due to sampling will significantly reduce the actual operation rate. If this pinhole defect is to be inspected and removed at the stage after printing is completed, it is necessary to join it with an adhesive tape in order to return it to a continuous film shape after cutting. For this reason, a seam is inserted, and a defective product is generated in the part and the front and back due to the influence of the seam, and the defective package must be removed during the process. In high-precision printing, the print pitch is reduced (shrinkage over time) due to the shrinkage of the film after printing, and it is difficult to control because it constantly changes under the flow temperature condition. Therefore, for vinyl chloride shrink film, cold storage cars and low temperature warehouses are required.

(D) Occurrence of Craze Polystyrene is apt to cause craze, which is a problem in the appearance of the product, and craze due to chemicals is also likely to occur.

(E) Destruction of Labels on Containers In the above-mentioned fusing seal and ultrasonic seal, the seal portion is apt to be broken due to a drop impact of the containers and the like and lacks in protection.

(F) White turbidity In the high temperature bonded product, the film which has been bent in the oriented state returns to the non-oriented state and is whitened by post-processing such as heat sterilization.

(G) Processing Speed and Bonding Strength of Joined Section Ultrasonic processing has already been put into practical use for tube processing of polyester polymers, and it is also considered to bond it with an adhesive for test purposes. However, in the case of ultrasonic sealing,
If a sufficient seal strength is to be obtained, joining can be performed only at an extremely low speed, and productivity is low, so that tube processing cost is high. Further, the ultrasonic sealing process operates sensitively by adjusting the gap of the oscillator, causes variations in the strength of the joint, and deforms and damages the base material, which causes embrittlement and damage.

On the other hand, the bonding with the adhesive is common sense at first glance, but unlike the general bonding with the laminate or coating, the film is folded and then bonded, so that the bonding portion is easily separated due to the repulsive action based on the elasticity of the film. There is a problem. In order to prevent this, an adhesive that instantaneously gives a high tack force is required, and in such a case, the coating workability becomes low. Even if it could be successfully joined, if the adhesive was heated and softened by the heat sterilization treatment in the subsequent process and the film was shrunk due to the shrinking stress of the film, the joint became jagged and the adhesive spilled out. In such a state, only that part gives an appearance different from the original film surface, and there is a problem in commercial value.

[0012]

SUMMARY OF THE INVENTION The gist of the present invention is telephony.
At the time of rolling a polyester film, which is one in which talic acid and isophthalic acid are used as essential acid components, to obtain a tubular body , a halogenated hydrocarbon solvent or ether solvent is provided on at least one surface of the joint surface of the tube. > Is applied and bonded at a temperature of 70 ° C. or lower before drying to obtain a tubular body.

[0013]

[Function] The industrial waste problem has been greatly taken up with the advent of plastic bottles, the recoverability has been examined to avoid it, and it is important to avoid chlorine gas and smoke damage during incineration. Among them, polyester tubes are attracting attention.

Further, a tube which can meet the demands for automation of packaging, speeding up, extension of life, etc., that is, a tube having rigidity enough to withstand high-speed workability and capable of withstanding heat sterilization has been studied. However, a heat-shrinkable tube that meets the above-mentioned demand has not been completed yet. More recently, printing effects,
There is a strong tendency for high-quality printing due to the ease of viewing the display, PR effects, etc.
As a general tendency, a film having dimensional stability is required. This also applies to a heat-shrinkable tube, and it is necessary to exhibit dimensional stability in the natural circulation process while having a heat-shrinkable property.

Polyester tubes have been developed to satisfy these demands, but unfortunately various problems have been encountered in the tube forming process.
Even if it is a polyester tube, it is possible to manufacture it by applying the conventional ultrasonic sealing method or adhesive bonding method to the polyester film, but as mentioned above, the processing speed is low and the variation is large, Furthermore, the joint may trigger the destruction, or the joint may peel off when the tube is heat-shrinked and covered and then heat sterilized, and the displacement due to softening often causes a problem on the appearance of the product. .
Therefore, we have established a technique of melt-integrating by using a solvent or a swelling agent without any adhesive other than the base film, and have solved all the above-mentioned problems.

The operational effects obtained by adopting the method of the present invention can be summarized as follows if they are clarified by comparison with the above problems.

(A) Regarding industrial disposal problems, by using a tube that does not generate chlorine gas and is of the same flow as a polyester bottle that has recently been circulating rapidly,
Turning work is also easier. The present invention solves this problem by using a polyester film.

(B) The problem of insufficient heat resistance has been solved by utilizing the excellent heat resistance of the polyester film, and it has succeeded in providing a tube capable of even high temperature hot water treatment such as retort treatment. In particular, the joint surface also needs to be able to withstand the high-temperature hot-water treatment, and it was decided to adhere without using an adhesive. That is, the greatest point of the present invention lies in the fact that the melt integration by the solvent or the swelling agent is realized, but as the solvent or the swelling agent, an organic solvent, that is, one which exhibits a dissolving action or a swelling action with respect to polyester is selected It Among them, halogenated hydrocarbon solvents and ether solvents are useful, and when these are used for bonding, particularly excellent properties (particularly adhesive strength) are exhibited.

(C) Regarding the printability, it is necessary to prevent the generation of gel which causes pinholes. Therefore, use a polyester polymer having excellent thermal stability and use many additives. Was stopped to obtain surface smoothness. Instead of adjusting various properties with various additives, the acid component and alcohol component of the polyester polymer are changed, and the basic properties are adjusted by changing the molecular structure. Settled. In addition, the glass transition temperature is set to 3 in order to prevent the trouble of printing pitch shrinkage after printing.
It is particularly recommended to use polyester polymers at 5 ° C or above. If the glass transition temperature is less than 35 ° C., the printing pitch changes in the natural circulation process, which requires transportation in a cold storage vehicle or storage in a low-temperature warehouse, which causes trouble in quality control. Therefore the polyester film of the present invention, the polyester copolymer having a glass transition temperature using terephthalic acid and isophthalic <br/> Le acids above 35 ° C. as essential acid components amount,
The film formed from a mixture of the polymer and at least one other polymer is most useful. That is, considering the industrial production of the present invention as a polyester-based polymer than polyethylene terephthalate homopolymer,
Use terephthalic acid and isophthalic acid as essential acid component
From the glass transition temperature of polyethylene terephthalate
Also , it is desirable that the polyester copolymer is lowered by about 1 ° C. or more , or a mixture containing this copolymer as a main component. In particular, when a halogenated hydrocarbon or an ether solvent is used as the solvent , high-speed and stable bonding strength can be obtained by selecting the above polyester.

Regarding the generation of (d) craze, the polyester polymer originally has a characteristic that no craze occurs. (e) Regarding the phenomenon of containers falling or being destroyed by the impact force during transportation, studies were conducted so that they would not occur at the joints of tubular bodies and that the films would not be essentially damaged. This was achieved by using a solvent, and it succeeded in obtaining a strong bond without damaging the substrate. Halogenated hydrocarbon solvents and ether solvents have been particularly useful in this respect.

(F) White turbidity is caused by heating the joint portion and causing it to be unoriented. Therefore, in the present invention employing a simple solvent joining means, heating is not carried out. It was possible to prevent the whitening phenomenon. That is, they succeeded in preventing the deterioration of the base material.

(G) In the present invention, the processing speed of the joining portion is such that when a polyester film is rolled to obtain a tubular body, a solvent or a swelling agent is applied to at least one of the joining surfaces and the joining is carried out before drying. As a result, it was possible to increase the speed and obtain a strong bonding strength.

Among the solvents or swelling agents used in the present invention, particularly recommended halogenated hydrocarbon solvents include low boiling point solvents as described below. That is, it consists of aliphatic and aromatic halogenated hydrocarbons and has a boiling point of 2
Vapor pressure of 5 mmHg or more at 20 ° C at 00 ° C or less, boiling point of 150 ° C or less, especially when considering high-speed tube processing, 20
It is preferable that the vapor pressure at 30 ° C. is 30 mmHg or more.

Illustrative examples are methylene chloride, chloroform, acetylene dichloride, ethylidene dichloride, ethylene dichloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,2,2-tetra. Solvents such as chloroethane, trichloroethylene, halogenated aliphatic hydrocarbons such as dichloropropylene and halogenated aromatic hydrocarbons such as ortho-dichlorobenzene can be used. Of course, the present invention is not limited to this, but a solvent capable of dissolving the polyester polymer of the present invention and having the above-mentioned boiling point and vapor pressure is most advantageous. Examples of applicable solvents other than halogenated hydrocarbon solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and trimethylbenzene; phenols such as phenol and metacresol; alcohols such as benzyl alcohol; nitrobenzenes. Nitrohydrocarbons, nitriles such as acetonitrile, nitriding compounds such as amines such as normal butyl amine, pyridine and morpholine; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cyclohexane; glycol ethers such as dioxane, tetrahydrofuran etc. Ethers such as furans; Esters such as ethyl acetate, normal butyl acetate, monoethyl acetate; Formic acid, acetic acid,
Organic acids such as fluoroacetic acid; inorganic acids such as sulfuric acid and nitric acid; sulfur derivatives such as carbon disulfide; N, N-dimethylformamide and the like are used, and particularly highly volatile ones are preferable.
Of the ether solvents, dioxane is particularly useful.

The solvent or swelling agent preferably has a solubility index of
Those in the range of 8.0 to 13.8 are good, but of course they are not limited to this range. From another point of view, the solvent or swelling agent preferably has a swelling degree of 1% or more when a polyester film of 5 cm × 1 cm × 40 μm is dipped at 23 ° C. for 10 seconds, but is not limited thereto.

Swelling degree = 100 × (A−B) / B (%) A: Film thickness after immersion B: Film thickness before immersion Further, the above is shown only as an example, and is of course limited to these. Further, the solvent swelling agent may be used alone or in combination.

[0027]

【Example】

Example 1 A polyester polymer of a polyethylene (tele / iso) phthalate copolymer (tele / iso ratio = 80/20) was polymerized so as to have an intrinsic viscosity of 0.75 dl / g, and silicon dioxide was added.
An unstretched film was manufactured by mixing 0.05% by weight and melt-extruding.

The film was mainly stretched in the transverse direction to produce a heat-shrinkable polyester film having a degree of transverse orientation of 104 × 10 ^-3 and a thickness of 40 μm. 72 with the film
Printing was performed with a width of 0 mm, and after printing, it was cut into a width of 230 mm. The shredded film is placed on a tube forming machine, methylene chloride is applied to one surface of the film, and immediately (while not drying)
The films were overlaid and processed into tubular bodies. The processing speed was 80 m / min. Cover the tube on a single service bottle and heat shrink at 100 ° C. for 5 seconds,
Then, sterilization heat treatment was performed at 110 ° C. for 30 minutes.

On the other hand, a tube adhesion test was performed on the film of the present invention using a general-purpose dry laminating adhesive (manufactured by Toyo Morton Co., Ltd.) (Comparative Example 1). Further, vinyl chloride (Comparative Example 2) and polystyrene (Comparative Example 3) were similarly tested.

[0030]

[Table 1]

As shown in Table 1, it was shown that the tube of the present invention has the same characteristics as those of the base material and is integrally joined, without any change in appearance and strength in the normal state due to each heat history. Further, in place of the methylene chloride used in Example 1, a geo
Even when xane is used as the bonding solvent, it is excellent as in Example 1.
It was confirmed that a tube with excellent performance was obtained.

Example 2 The acid component comprises terephthalic acid, isophthalic acid and orthophthalic acid, and the alcohol component comprises a polyester polymer comprising ethylene glycol and diethylene glycol. The former is 80: 15: 5 and the latter is 70:30. The resulting polyester polymer was oriented in the same manner as in Example 1 so that the degree of orientation in the lateral direction was 98 × 10 ⁻³ . The obtained film having a thickness of 30 μm was cut into a width of 720 mm and then printed.

After printing, the product was further shredded into a width of 230 mm, and ethane dichloride was thinly applied at a speed of 60 m / min to the plain part of the end,
Bonded immediately (while not drying). Immediately after joining, the film was taken up by a winder, but the joined part could be processed without coming off. For comparison with these, an ultrasonically sealed tube (Comparative Example 4) was processed at a low speed of 10 m / min.
The performance of the obtained tube was as shown in Table 2.

[0034]

[Table 2]

Example 3 Degree of transverse orientation produced in Example 1: 104 × 10 ⁻³ , thickness 4
720 using 0 μm heat shrinkable polyester film
Printing was performed with a width of mm, and after printing, it was cut into a width of 230 mm. 50m of trichlorethylene with 94% swelling on the plain part of the edge
A thin coat was applied at a speed of / min and the bond was made immediately (while not drying). The joint could be processed without coming off. Table 3 shows the performance of the ultrasonically sealed tube (Comparative Example 5) for comparison with these.

[0036]

[Table 3]

<Stability of printing pitch> Regarding the stability of printing pitch, the following results were obtained. Printing pitch is plate length 1
The pitch length of the printed product was also measured against 15 mm. As Comparative Example 6, electric wire cross-linked polyethylene was used, and the results are shown in Table 4.

[0038]

[Table 4]

[0039]

【The invention's effect】

(a) With respect to heat resistance, it shows superior characteristics to conventional tubes due to 95 ° C boil treatment, 125 ° C retort treatment, etc.
In addition, the joints had practical properties that could not be obtained by simple adhesive joining.

(B) As shown in Table 4, the product of the present invention maintained a dimension close to the plate length for a long time. This is a very important characteristic for matching the printed pattern and the shape of the packaged object. As a result, it is possible to position the printed pattern at a predetermined position.

(C) As a result of trying the drop fracture test of the glass bottle, as shown in Tables 1 and 2, the flying distance is extremely short.
In particular, it can be seen that the state of the joint has a significant effect on this characteristic. The fact that there is no change between the film substrate and the joint in terms of impact rupture properties is extremely advantageous in terms of risk prevention by bottle breaking.

(D) The turbidity of the bonded portion is easily caused by the boil treatment, the retort treatment and the like, but the turbidity of the heat-sealed portion which is a defect of the polyester film tube can be sufficiently prevented in the present invention.

In Comparative Example 1 in Table 1, the films of the present invention were joined with an adhesive and heated at 80 ° C., and both the boiling and retorting treatments which were subsequently carried out after the heat shrinkage,
It becomes cloudy. It is considered that this is due to a decrease in the degree of orientation of the heated joint portion, which facilitated crystallization and turned cloudy. Since the tube of the present invention was processed without applying a temperature that disturbs the orientation, this phenomenon was not observed at all.

(E) Some examples of the joining processing speed are shown in the examples, but practical strength can be obtained only at a low speed of 5 to 15 m / min for ultrasonic sealing and 0.1 to 1 m / min for solvent-based adhesive. Absent. In addition, as seen from the ultrasonic sealing, the impact strength of the joint is weak, so the bottle is easily broken and the protective function deteriorates. In addition, even if the present invention is used for heat-bonding as shown in Comparative Example 1 of Table 1, the shrinkage of the bonded part after heat-shrinking causes a change in characteristics different from those of the base film, so that the same state of finish is obtained. As a result, floating, wrinkles, fishing, etc. occur.

As shown in Example 1, the present invention can process up to 80 m / min as an example, and can process up to several hundred m / min depending on the conditions, and it can be incorporated in an integrated line connected to an automatic labeling machine. I showed the speed that I was able to do.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08L 67:00

Claims (2)

[Claims] 1. Essential terephthalic acid and isophthalic acid
When a tubular film is obtained by rolling a polyester film used as an acid component , a halogenated hydrocarbon solvent is formed on at least one surface of the joint surface of the tube.
Alternatively , apply an ether solvent and dry at 70 ° C or above before drying.
A method for producing a polyester tube, which comprises joining at a lower temperature to obtain a tubular body. 2. The polyester film is terephthalic acid and isophthalic acid having a glass transition temperature of 35 ° C. or higher.
2. The method according to claim 1, wherein the film is formed by a polyester copolymer using as an essential acid component or a mixture of the copolymer with at least one other polymer.