JPH10259258A - Thermally shrinkable film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film high in safety for human bodies and capable of preventing the adhesion of aquatic organisms to the film over a long period by adding an antifouling agent to a thermally fusible resin having a film-forming property and subsequently forming the composition into the thermally shrinkable film. SOLUTION: This film contains (A) 1-20wt.% of an antifouling agent [preferably a compound of the formula (R1, R2 are each a hydrocarbon group, a halogen; Y is a 4-20C hydrocarbon)] and has a thermal fusion temperature of <=180 deg.C between the films. A polymer for forming the film is preferably a polymer having a melting point or softening point of <=200 deg.C, especially preferably a polyester resin. The film preferably has a longitudinal thermal shrinkage of >=2% and a lateral thermal shrinkage of <=30% at the thermal fusion temperature. Thereby, the objective film high in safety for human bodies, excellent in handleability and high in durability is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-shrinkable film having an aquatic organism adhesion preventing effect.

[0002]

2. Description of the Related Art Conventionally, fishing nets such as ships, stationary nets and aquaculture nets have arthropods such as barnacles, mollusks such as mussels, coelenterates such as anemones and hydroids, and sponges such as sponges on the surface thereof. , Annelids such as Uzumakigokai, Algae such as Aosa and diatoms are liable to adhere, which increases the resistance of ships due to seawater and causes damage such as increased fuel efficiency.
In addition, fishing nets suffered damage due to increased resistance to waves and tidal currents, which caused them to be washed away or to sink due to increased weight. To prevent such damage, organotin-based antifouling agents have been widely used. However, the organotin-based antifouling agent was found to be harmful to humans in the food chain of plankton and small animals that feed on it, and fish that feed on them, as a result, In recent years, toxicity to the human body has become a social problem and has been virtually banned.

On the other hand, efforts have been made to develop a safer antifouling agent, and a copper-based antifouling agent and various chemical agents have been proposed. The effects of solvents on the human body and air pollution have become new problems. In addition, when these chemical agents are used by dyeing with a net, the durability of the antifouling effect is much lower than that of the organotin-based antifouling agent, and the handling thereof is extremely poor. In particular, an antifouling formulation which is easy to handle and has high durability is desired for molded articles such as poles used for cultivation of floats and laver and ropes.

[0004]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a heat-shrinkable film having high safety to the human body, excellent handling properties, high durability and a long-term effect of preventing aquatic organisms from adhering to water. To provide.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a resin having a heat-sealing property and a film-forming ability contains an antifouling agent. It has been found that the above-mentioned problems can be solved by forming a film into a heat-shrinkable film, which has led to the present invention.

That is, the present invention provides a film containing 1% by weight or more and 20% by weight or less of an antifouling agent, wherein the film has a heat welding temperature of 180 ° C. or less. Film. As the antifouling agent used in the present invention, dimethyldithiocarbamic acid, 2
-Methyl-thio-4-t-butylamino-6-cyclopropylamino-S-triazine, 2,4,5,6-tetrachloroisophthalonitrile, M, N-dimethyldichlorophenylurea, 4,5-dichloro- 2-n-octyl-3 (2H) isothiazoline, N-fluorodichloromethylthiosulfamide, 2-pyridinethiol-1-oxide zinc, 2,3,5,6-tetrachloro-4-methylsulfonylpyridine, 3 -Iodo-2-propylbutylcarbamate, diiodomethylparatrisulfone,
Bisdimethyldithiocarbamoyl zinc ethylene bisdithiocarbamate, phenylbispyridylbismuth dichloride, pyridinetriphenylborane and the like can be mentioned, but are not limited thereto. In addition, two or more types can be used in combination.

Particularly, a compound represented by the following formula (I) is preferably used as an antifouling agent.

Embedded image The compound is not only excellent in its aquatic organism adhesion prevention effect and durability, but also decomposes rapidly in the environment and rarely pollutes the environment. The compound may be used in combination with the other antifouling agents described above. As specific examples of the compound,
2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3one, 1,2
-Benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-
2-n-octyl-4-isothiazolin-3-one and the like can be mentioned. Two or more of these antifouling agents may be used in combination.

[0008] The content of these antifouling agents in the film is 1
It is necessary that the amount is not less than 20% by weight and not more than 20% by weight.
When the content of the antifouling agent is less than 1% by weight, not only the effect as the antifouling agent is insufficient, but also the durability of the effect of preventing adhesion of aquatic organisms becomes insufficient. On the other hand, if the content of the antifouling agent exceeds 20% by weight, the strength of the film may be reduced due to its plasticizing effect, and the problem of bleed out may occur. Therefore, the preferable content of the antifouling agent is 2% by weight or more and 15% by weight or less.

Further, in the present invention, as a result of examining the sustained-release properties of the above-mentioned antifouling agent, the content of the antifouling agent was 0.2%.
It has been found that the combined use of a specific chain hydrocarbon compound in a ratio of 2 times or more and 2 times or less greatly improves the sustained release of the antifouling agent. That is, such a compound is a chain hydrocarbon compound having a branch and a molecular weight of 500 or more. When the content of the chain hydrocarbon compound is less than 0.2 times the content of the antifouling agent, the sustained release effect is not sufficiently exhibited, and even when it exceeds 2 times, the sustained release effect is not obtained. Not only does it have no meaning to be added in a large amount because of saturation, but also a plasticizing effect is exhibited, which may cause adverse effects such as a decrease in film strength. The preferred content is 0.5 times or more and 1.5 times or less the antifouling agent content.

The molecular weight of the chain hydrocarbon compound is 5
It is preferably at least 00, particularly preferably at least 1500.
When the molecular weight is less than 500, the transfer of the on-chain hydrocarbon compound to the film surface becomes severe, and not only the handleability of the film is deteriorated, but also the chain hydrocarbon compound is expected to have an effect of improving the sustained release property. May be added, the chain hydrocarbon compound may migrate to the film surface and carry out the above-described antifouling agent to the film surface, resulting in a decrease in the long-term effectiveness of the antifouling agent. is there. The reason why such a chain hydrocarbon compound improves the sustained-release property is not clear, but it is presumed that the above-mentioned antifouling agent has an effect of satisfactorily holding the above-mentioned antifouling agent in an amorphous portion due to branching.

The term "branch" of the chain hydrocarbon compound means a straight-chain, branched, or cyclic group having about 1 to 20 carbon atoms, or a combination thereof. When the chain hydrocarbon compound is used in combination with the antifouling agent represented by the above formula (I), the sustained release effect of the antifouling agent is remarkably improved, and the long-term durability of the antifouling agent is improved. Will be noticeable.

Specific examples of the chain hydrocarbon compound include polyisoprene, liquid rubbers (liquid BR, liquid SBR, liquid N
BR, liquid chloroprene, liquid polyisobutylene, etc.),
Polybutene and the like can be mentioned. Among them, the formula (I)
Polybutene and liquid chloroprene are preferred as compounds that exhibit remarkable effects when used in combination with the compound represented by formula (1).

It is preferable that the film of the present invention has a property of shrinking during heat welding. That is, it is preferable that the heat shrinkage in the vertical direction of the film at the time of heat welding of the film is 2% or more and the heat shrinkage in the horizontal direction is 30% or less. Here, the vertical direction of the film indicates the length direction of the film, and the horizontal direction indicates the direction orthogonal to the length direction, that is, the width direction. In the case where the films are overlapped in the longitudinal direction and heat-welded, if a large shrinkage occurs in the horizontal direction of the film, the overlapping portion of the film is opened and the use of the heat-welding cannot be performed. If the area of the overlapping portion is made large in order to prevent the overlapping portion of the film from being opened, the amount of the film used increases, which is very disadvantageous economically. Therefore, the heat shrinkage in the transverse direction of the film is 3
It is preferably 0% or less, particularly preferably 25% or less. For example, when winding a film around an object having a complicated shape such as a bent pole,
In order to prevent the occurrence of wrinkles generated on a surface having looseness or a curve, the heat shrinkage in the longitudinal direction of the film should be 2% or more, particularly 4% or more, in addition to the heat shrinkage in the horizontal direction of the film. Is preferred. The upper limit of the heat shrinkage in the longitudinal direction of the film is not particularly limited, but is preferably 30% or less in consideration of the degree of wrinkling of the film due to the shape of the object, the stress at the time of film shrinkage, and the like. In the present invention, the heat shrinkage of the film is desirably in the above-described range, and the conditions of a film forming method described later are appropriately set in consideration of the shape of the object, and the heat in two directions at the heat welding temperature of the films is determined. It is desirable to set the shrinkage in the above range.
For example, when the film is affixed to the bottom of a ship or the like, the smaller the heat shrinkage in two directions, the better.

The above-mentioned heat shrinkage ratio means a film cross-sectional area of 100
Apply a load of 0.01 g per μm ² , from room temperature to 10 ° C
The rate of shrinkage at the temperature at which the temperature was increased under dry heat at a rate of temperature increase of / min, and heat welding was performed was determined.

The polymer forming the film of the present invention is not particularly limited, and is preferably a polymer having a melting point or softening point of 200 ° C. or less, and a polymer having a melting point or softening point of 200 ° C. or less. The type is not limited as long as it is present, but is preferably a polyester resin in consideration of various physical properties such as durability and strength as a film. Usually, the polyester comprises a dicarboxylic acid component and a diol component. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, phthalic acid, α, β- (4-carboxyphenoxy) ethane. , 4,4'-dicarboxydiphenyl, 5
-Aromatic dicarboxylic acids such as sodium sulfoisophthalic acid; aliphatic dicarboxylic acids such as azelaic acid, adipic acid and sebacic acid and esters thereof. Examples of the diol component include ethylene glycol and diethylene glycol. 1,3-propanediol, 1,4
-Butanediol, 1,6-hexanediol, 1,9
-Nonanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, polyethylene glycol-
, Aliphatic tetra-methylene glycols such as
Catechol, bisphenol A, bisphenol A
And diols such as aromatic diols such as ethylene oxide adducts. Each component may be selected from the dicarboxylic acid component and the diol component so that the polyester has a melting point or a softening point of 200 ° C. or less. Each component may be a polyester obtained by copolymerizing not only one kind but also two or more kinds. In short, the melting point or the softening point is preferably 200 ° C. or less.

Among them, polyesters whose hexamethylene terephthalate unit accounts for at least 40 mol% of their constituent units have high crystallinity, prevention of sticking during drying, high film strength, excellent weather resistance and antifouling agents. It is preferable in terms of sustained release and the like.
The polyester preferably has an intrinsic viscosity in the range of 0.75 to 1.5, and the acid component copolymerized with the polyester as required includes the above-mentioned dicarboxylic acid component, for example, isophthalic acid, 5- Aromatic dicarboxylic acids such as sodium sulfoisophthalate and aliphatic dicarboxylic acids such as sebacic acid, adipic acid and azelaic acid can be used, and aromatic dicarboxylic acids are particularly preferable. As the diol component to be copolymerized as required, the diol component described above, for example, ethylene glycol,
1,3-propanediol, 1,4-butanediol,
Aliphatic diols such as 1,9-nonanediol and cyclohexanediol can be used. However, although the melting point or softening point is lowered by the modification, 1,1 is relatively less likely to inhibit crystallinity. It is preferable to use 4-butanediol.

The film of the present invention can be produced by a known film forming method. For example, a casting method, an extruder method, a calendar roll method and the like can be mentioned. When the above-mentioned polyester resin is used, the extruder method is preferable, and the T-die method, inflation method and the like.
It may be manufactured by any of the methods. The unstretched film produced by such a method may be subsequently subjected to a stretching treatment, but may be used without stretching if it has the above-mentioned heat shrinkage in the unstretched state. When a stretching treatment is applied to an unstretched film, there are a uniaxial stretching method, a biaxial stretching method, and the like, and it may or may not be subjected to heat setting after stretching. In short, it is preferable to produce a film by a method that satisfies the above-mentioned heat shrinkage.

The heat-shrinkable film produced in this manner is used as an object to be used, for example, ropes used for ships, fixed nets, and culture nets, and suspension ropes used for culturing pearl oysters and oysters. It is used by cutting it into a predetermined shape according to the shape of poles used for cultivation of breeds, floats, laver and the like. Then, it is fixed to the object to be used by heat welding at a temperature of 180 ° C. or less. The method of heat welding includes heat sealing, impulse sealing, ultrasonic bonding, etc., and can be appropriately selected depending on the shape of the object. Depending on the shape of the object to be used, the film can be applied to the object only by thermal welding of the films,
Even if a commercially available adhesive or pressure-sensitive adhesive is used in order to further enhance the adhesiveness and the adhesiveness of the film to the object, it may be used.

[0019]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition, each measured value in an Example is a value measured and calculated by the following method. (1) Intrinsic viscosity of polyester It is a value measured and calculated at 30 ° C. using a mixed solution of phenol / tetrachloroethane by weight. (2) Evaluation of the effect of preventing aquatic organisms from adhering In Zumei Bay, Okayama Prefecture, samples were taken for one year, 1-2 m below sea level.
And observe the status of aquatic organisms every two months,
Judgment was made based on the following criteria. Evaluation criteria: 1: No attachment of aquatic organisms is observed. 2: Adhesion of aquatic organisms was observed on about 25% of the sample surface. 3: Adhesion of aquatic organisms was observed on about 50% of the specimen surface. 4: Adhesion of aquatic organisms was observed on about 75% of the specimen surface. 5: Adhesion of aquatic organisms was observed on almost the entire surface of the specimen.

(3) Evaluation of heat welding processability of film Using a hand-held hot air generator equipped with a temperature adjusting mechanism (Heat Gun MDEL-882, manufactured by Hakuko Co., Ltd.), a film was formed in an aluminum tube having a diameter of 5 cm. A film sample having a width of 5 cm was adjusted so that the overlapping portion became 5 mm, and the overlapping portion was heat-sealed at a predetermined temperature to evaluate. Evaluation criteria: A: Fusing processing was possible without distortion easily. ：: Thermal fusion was possible. Δ: Partially distorted, a gap was generated. ×: The overlapped portion was opened, and there was a problem in the heat fusion property.

Example 1 Polyhexamethylene terephthalate having an intrinsic viscosity of 0.98 was mixed with 5% by weight of 4,5-dichloro-2-n-octylisothiazolin-3-one as an antifouling agent and kneaded.
This was formed into a film by a film forming apparatus, and further subjected to a heat setting treatment for stretching and adjusting the shrinkage ratio, thereby obtaining a film having a shrinkage ratio in the length direction of the film of 15% and a shrinkage ratio in the width direction of 25%. The obtained film was cut into a width of 10 cm and wound up. This film was fitted to an aluminum pipe having a diameter of 5 cm and a length of 1 m, and a mesh width of 3 cm and an angle with the pipe axis of 3 mm.
Spirally wound at 0 °, and heat-sealed 16 times.
Performed at 5 ° C. Further, the pipe was immersed in the sea of Moomin Bay, Okayama Prefecture for one year, and the effect of preventing aquatic organisms from adhering was evaluated. Table 3 shows the results of each evaluation. There is no problem of shrinkage at the time of heat fusion, the effect of preventing aquatic organisms from adhering after one year is good, and the effect can be expected to last for a long time.

Examples 2 to 14 In the same manner as in Example 1, an antifouling agent was added to the resin shown in Table 1.
A film was prepared by incorporating a sustained release agent as needed.
Table 2 shows the shrinkage ratios of the obtained films. The film was wound around an aluminum pipe in the same manner as in Example 1 and subjected to a heat fusion treatment. Then, it was immersed in seawater to evaluate the effect of preventing aquatic organisms from adhering. Table 3 shows the results of each evaluation. In the second embodiment, the joint width is set to 5 mm, and the joint width is set to 16 mm.
Heat fusion at 5 ° C. resulted in stable fusion without opening the joint due to shrinkage. Also, the results of the immersion test in Zumyo Bay were good. In Example 8, the aluminum pipe was wound with some loose wrinkles intentionally, but could be fused without any problem. In Examples 9 to 14, the resin, the antifouling agent, and the type of the sustained release agent were changed and evaluated.
In each case, good results were obtained.

COMPARATIVE EXAMPLE 1 When polyethylene terephthalate having an intrinsic viscosity of 0.65 (melting point: 256 ° C.) was used as a resin, the antifouling agent was decomposed due to the high fusion temperature of the film, and the antifouling agent was decomposed. A large amount of aquatic organisms were found to adhere as in the case of a commercially available polyester film to which no was added. Table 5 shows the results.

Comparative Example 2 When a polyester having a melting point of 200 ° C. (polyethylene terephthalate modified with 20% by mole of isophthalic acid) was used as a resin, the fusion temperature of the film was increased, and the antifouling agent was decomposed. When welded to the aluminum pipe, a slight gap was formed at the seam, so that aquatic organisms attached in two months.

Comparative Example 3 Polyester having a melting point of 184 ° C. (polybutylene terephthalate modified with 20% by mole of isophthalic acid) was used as a resin.
Thermal decomposition of the antifouling agent progressed, and a slight gap was formed at the seam when the antifouling agent was fused to the aluminum pipe, so that aquatic organisms adhered in three months.

Comparative Example 4 When a polyester having a melting point of 210 ° C. (isophthalic acid 20 mol% modified polyethylene terephthalate) was used as a resin, it could be fused only at 185 ° C.
Thermal decomposition of the antifouling agent progressed, and a slight gap was formed at the seam when the antifouling agent was fused to the aluminum pipe, so that aquatic organisms adhered in three months.

Comparative Example 5 When the content of the antifouling agent was increased, bleeding out of the antifouling agent to the film surface occurred, and an insufficiently fused portion was formed in the heat-sealed portion of the film. As a result, the film was peeled off while suspended in the seawater of Zumyo Bay, and aquatic organisms were found to adhere to the peeled portion. Further, the bleed-out antifouling agent causes a problem in handling of the processed pipe.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

[0032]

[Table 5]

[0033]

The film of the present invention can be heat-sealed to a complicated shape and has not only an effect of preventing aquatic organisms from adhering for a long period of time, but also processing again when the effect is reduced after long-term use. Can be used.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29C 61/06 B29C 61/06 B29K 67:00 105: 02 B29L 7:00 (72) Inventor Masahiko Nanjo Kurashiki-shi, Okayama 1621 Sazu, Kuraray Co., Ltd. (72) Inventor Shingo Nakanishi 2-5-4, Hiranocho, Chuo-ku, Osaka-shi Kura Retailing Co., Ltd.

Claims (5)

[Claims] 1. A heat-shrinkable film comprising a film containing 1% to 20% by weight of an antifouling agent, wherein the film has a heat welding temperature of 180 ° C. or less. 2. A heat shrinkage rate in a longitudinal direction at a heat welding temperature of 2
The heat shrinkable film according to claim 1, wherein the heat shrinkage in the transverse direction is 30% or less. 3. The heat-shrinkable film according to claim 1, comprising a polyester resin. 4. The heat-shrinkable film according to claim 1, wherein the antifouling agent is a compound represented by the following general formula (I). Embedded image 5. The method according to claim 1, wherein a chain hydrocarbon having a branch and a molecular weight of 500 or more is contained in an amount of 0.2 to 2 times the content of the antifouling agent. 4. The heat-shrinkable film according to any one of 4.