JP2007293212A - Heat-shrinkable polyester film label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrinkable polyester film label excellent in various properties such as processing suitability, slidability, and antistatic property. <P>SOLUTION: The heat-shrinkable polyester film label has, at least on one side, a slippery layer containing a silicon containing ingredient as an outermost layer. The dynamic friction coefficient μd between outer faces of the film label is <0.30 and the surface resistivity of at least one side of the film label is ≤1×10<SP>14</SP>(Ω/square) in the atmosphere of a temperature 23°C and a relative humidity 65%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a heat-shrinkable polyester film, and more specifically, it is suitable for a vending machine beverage label because it has good sliding properties when used as a beverage bottle label film, and is processed in a printing process or a tubing process. The present invention relates to a heat-shrinkable polyester film having excellent properties.

In recent years, for the purpose of packaging to improve the appearance of packaging, packaging to avoid direct impact of contents, label packaging that protects glass bottles or plastic bottles and displays products, etc.
A heat-shrinkable plastic film having a property of shrinking by heating is widely used. Plastic materials used for these purposes include stretched films such as polyvinyl chloride films, polystyrene films, and polyester films. Labels are used in various containers such as polyethylene terephthalate (PET) containers, polyethylene containers, and glass containers. And used for the purpose of cap seals or integrated packaging.

  In order to produce labels and the like, the following methods are usually employed. That is, the raw polymer is continuously melt extruded to produce an unstretched film. Next, stretching is performed to obtain a film roll. While feeding out the film from this film roll, it is slit to a desired width and wound into a roll again. Subsequently, character information such as various product names and designs are printed. After the printing is finished, the tube is manufactured by overlapping and joining the left and right ends of the film by means such as solvent bonding (tubing process). The slit process and the printing process may be reversed in order. If the obtained tube is cut into a suitable length, it becomes a cylindrical label, and a bag can be manufactured by joining one open end of this cylindrical label.

  And the inside of the shrink tunnel (steam tunnel) of the type that covers the label or bag etc. on the container and blows and heat shrinks by steam, and the shrink tunnel (hot air tunnel) of the type that blows hot air and heat shrinks, A final product (labeled container) is obtained by passing it on a belt conveyor or the like, and heat-shrinking a label, a bag, or the like so as to be in close contact with the container.

In addition, when used as a label for bottled beverages, when products are transported inside the vending machine, the products may not be able to reach the outlet due to insufficient slipping of the labels, May adhere to the inner surface of the film and may be discharged multiple times.
To solve this problem, there has been a method of laminating a layer having good slipperiness on the film surface (see, for example, Patent Document 1).
JP 2004-114358 A

  However, although slipperiness is improved, there is a problem that dirt is attached to the product due to generation of static electricity.

Troubles caused by static electricity include, for example, wrapping around rolls, shocks to the human body, difficulty in handling such as winding in rolls in production processes, printing, adhesion, and other secondary processing processes, generation of printing whiskers, film surface It is a dirty and a decline in commercial value. From the viewpoint of preventing these, the film during processing preferably has a surface resistivity of at least one surface of less than 1 × 10 ¹⁴ (Ω / □), more preferably a surface resistivity of 1 × 10 ¹² (Ω / □). ) Is recommended.

Further, when the label is in a state of being easily charged with static electricity in a state where it is attached to a bottled beverage, dust is likely to adhere to the label, resulting in poor appearance due to dirt, that is, a reduction in commercial value. In order to prevent this, as described above, heat shrink treatment is performed by using a shrink tunnel (steam tunnel) that blows steam to cause heat shrink or a shrink tunnel (hot air tunnel) that blows hot air to shrink. When mounted on the bottle, the surface resistivity of at least one surface is preferably 1 × 10 ¹⁴ (Ω / □) or less, more preferably 1 × 10 ¹³ (Ω / □) or less. Is recommended.

  The present invention aims to provide a heat-shrinkable film that can solve the various problems of the above-mentioned conventional heat-shrinkable film. Specifically, it has various properties such as processability, slipperiness, and antistatic properties. An object was to provide an excellent heat-shrinkable polyester film label.

The heat-shrinkable polyester film label of the present invention has an easy-sliding layer containing a silicone-containing component as an outermost layer on at least one surface, and the dynamic friction coefficient μd between the film label outer surfaces is less than 0.30, The main point is that the surface resistivity of one surface is 1 × 10 ¹⁴ (Ω / □) or less in an atmosphere of a temperature of 23 ° C. and a relative humidity of 65%.

The heat-shrinkable polyester film label having the above-mentioned characteristics can prevent clogging in a vending machine when used as a label for a bottled beverage by satisfying the above-mentioned coefficient of friction coefficient. Satisfying the specific resistance value prevents the generation of static electricity and prevents the appearance from being deteriorated due to the adhesion of dirt.

  The heat-shrinkable film label of the present invention is excellent in slipperiness and can prevent clogging in a vending machine when used as a label for bottled beverages, etc., and also has excellent antistatic performance due to adhesion of dirt. Appearance deterioration can be prevented. Therefore, it is very useful as a label for covering containers such as bottled beverages.

In terms of slipperiness, the film label of the present invention must have a coefficient of dynamic friction μd between the outer surface of the label, that is, the surface not in contact with the container, of less than 0.30. When μd satisfies the above range, it is possible to provide a film having good slipperiness in the vending machine when used as a label for a beverage bottle, for example, the contact area with the inside of the vending machine is large and clogging occurs. Even if it is a square bottle which is easy to do, generation | occurrence | production of clogging can be prevented. However, if it exceeds this range, the slipperiness becomes insufficient, and troubles such as clogging of containers with vending machines occur. More preferably, the dynamic friction coefficient μd of the film label is 0.28 or less. The dynamic friction coefficient μd on the outer surface of the film label is a value measured in an environment of 23 ° C. and 65% RH in accordance with JIS K7125. Furthermore, the surface specific resistance value of at least one surface must be 1 × 10 ¹⁴ (Ω / □) or less in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%. When the surface resistance value satisfies the above range, it is possible to prevent adhesion of dirt due to the influence of static electricity, that is, deterioration of the appearance of the beverage container. However, if it exceeds this range, the label is likely to be charged, and an appearance defect due to dirt adhesion tends to occur.

  The composition and production method of the heat-shrinkable film label of the present invention are not particularly limited as long as each of the above-described characteristics is satisfied. Preferred embodiments will be described below.

  The polyester resin constituting the heat-shrinkable film of the present invention uses, as a dicarboxylic acid component, one or more of aromatic dicarboxylic acids, their ester-forming derivatives, and aliphatic dicarboxylic acids, and polycondensation with a polyhydric alcohol component. The known (copolymerized) polyesters can be used. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, naphthalene-1,4- or -2,6-dicarboxylic acid, and 5-sodium sulfoisophthalic acid. Examples of these ester derivatives include derivatives such as dialkyl esters and diaryl esters. Examples of the aliphatic dicarboxylic acid include dimer acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, oxalic acid, and succinic acid. Further, an oxycarboxylic acid such as p-oxybenzoic acid, and a polyvalent carboxylic acid such as trimellitic anhydride and pyromellitic anhydride may be used in combination as necessary.

Examples of the polyhydric alcohol component include ethylene glycol, diethylene glycol, dimer diol, propylene glycol, triethylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, 3- Alkylene glycols such as methyl 1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, Examples include alkylene oxide adducts of bisphenol compounds or derivatives thereof, trimethylolpropane, glycerin, pentaerythritol, polyoxytetramethylene glycol, polyethylene glycol and the like. Moreover, although it is not a polyhydric alcohol, (epsilon) -caprolactone can also be used.

The polyester raw material which comprises a polyester-type heat-shrinkable film may be individual, and may mix and use 2 or more types. When used alone, homopolyesters other than polyethylene terephthalate such as polybutylene terephthalate, polycyclohexylene dimethyl terephthalate, and polyethylene naphthalate are preferable. This is because polyethylene terephthalate alone does not exhibit heat shrinkability.

However, in consideration of the tear resistance, strength, heat resistance, etc. of the film, the crystalline ethylene terephthalate unit is preferably the main constituent component. Specifically, in 100 mol% of the constituent unit of the polyester raw material, ethylene It is recommended to select the terephthalate unit to be 50 mol% or more. Therefore, it is preferable that 50 mol% or more of the terephthalic acid component in 100 mol% of the dicarboxylic acid component and 50 mol% or more of the ethylene glycol component in 100 mol% of the polyhydric alcohol component. As for an ethylene terephthalate unit, 55 mol% or more is more preferable, and 60 mol% or more is further more preferable. It is recommended that the units other than the ethylene terephthalate unit be 5 mol% or more, preferably 7 mol% or more, more preferably 9 mol% or more in 100 mol% of the constituent unit of the polyester raw material. It is because it becomes possible to ensure the solvent adhesiveness and heat shrinkability of the film by introducing the amorphous improvement component to the above extent.

From the viewpoint of heat shrinkage characteristics and productivity, it is preferable to use a blend of two or more polyesters having different Tg. It is preferable to use a mixture of polyethylene terephthalate and copolymerized polyester (which may be two or more types), but it may be a combination of copolymerized polyesters. Moreover, polybutylene terephthalate, polycyclohexylene dimethyl terephthalate, and polyethylene naphthalate can be combined, or these can be used in combination with other copolyesters. Three types of blends of polyethylene terephthalate, polybutylene terephthalate, a mixed diol component of ethylene glycol and neopentyl glycol, and a copolyester composed of terephthalic acid are most preferable in terms of heat shrinkage characteristics. When two or more polyesters are used in combination, it is preferable from the viewpoint of production efficiency that the respective polymer chips are blended in a hopper.

Polyesters can be produced by melt polymerization in the usual way, but the so-called direct polymerization method in which oligomers obtained by direct reaction of dicarboxylic acids and glycols are polycondensed, dimethyl ester of dicarboxylic acid and glycol are transesterified. Examples include a so-called transesterification method in which polycondensation is performed after the reaction, and any production method can be applied. Moreover, the polyester obtained by another polymerization method may be sufficient. The polymerization degree of polyester is preferably 0.3 to 1.3 dl / g in terms of intrinsic viscosity.

In addition to polymerization catalysts such as antimony oxide, germanium oxide, and titanium compounds, polyester such as magnesium acetate, magnesium chloride and other Mg salts, calcium acetate, calcium chloride, etc. Ca salt, manganese acetate, manganese chloride and other Mn salts, zinc chloride, zinc acetate and other Zn salts, cobalt chloride, cobalt acetate and other Co salts, respectively, with respect to the polyester as 300 ppm or less, phosphoric acid or Phosphoric acid ester derivatives such as phosphoric acid trimethyl ester and phosphoric acid triethyl ester may be added in an amount of 200 ppm or less in terms of phosphorus (P).

If the total amount of metal ions other than the above polymerization catalyst is 300 ppm with respect to the polyester and the amount of P exceeds 200 ppm, not only the coloration of the polymer becomes remarkable, but also the heat resistance and hydrolysis resistance of the polymer are remarkably lowered. .

At this time, in terms of heat resistance, hydrolysis resistance, etc., the molar atomic ratio (P / M) of the total P amount (P) and the total metal ion amount (M) is 0.4 to 1.0. It is preferable. When the molar atomic ratio (P / M) is less than 0.4 or exceeds 1.0, it is not preferable because the film may be colored or coarse particles may be mixed in the film.

The timing of adding the above metal ions, phosphoric acid and derivatives thereof is not particularly limited. Generally, metal ions are added at the time of raw material charging, that is, before transesterification or esterification, and phosphoric acids are added before polycondensation reaction. It is preferable to do this.

In the heat-shrinkable polyester film of the present invention, inorganic particles, organic salt particles and crosslinked polymer particles can be added as a lubricant. Inorganic particles include calcium carbonate, kaolin, talc, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, riotium fluoride, etc. Is mentioned. In particular, in order to obtain a film having a lower haze while obtaining good handling properties, the inorganic particles are preferably aggregated silica particles formed by agglomerating primary particles. Examples of the organic salt particles include terephthalate such as calcium oxalate, calcium, barium, zinc, manganese, and magnesium.

Examples of the crosslinked polymer particles include homopolymers or copolymers of vinyl monomers such as divinylbenzene, styrene, acrylic acid or methacrylic acid. In addition, organic particles such as polytetrafluoroethylene, benzoguanamine resin, thermosetting urea resin, and thermosetting phenol resin may be used.

In addition, when trying to impart lubricity to the film, there is a method of roughening the surface with the above-mentioned lubricant particles and reducing the contact area. However, if too much is added, the transparency of the film is lowered and the commercial value is increased. It may be damaged. For this reason, it is preferable to use the said lubricant particle | grain at the level which suppresses the center surface average roughness in the 2nd surface of a film to 0.03 or less. Within this range, slipperiness can be imparted without impairing the transparency of the label film.

Examples of the method for adding the lubricant include a method in which the lubricant is dispersed in the polymerization step of the polyester used as the film material, or a method in which the polyester after polymerization is melted again and added. In order to disperse the lubricant uniformly over the entire length of the film roll, after dispersing the lubricant in the polyester by any of the methods described above, the shape of the polymer chip in which the lubricant is dispersed is matched and the raw material in the hopper It is preferable to suppress the segregation phenomenon. The polyester is taken out from the polymerization apparatus in the form of a strand in a molten state after polymerization, and immediately cooled with water, and then cut into a chip by a strand cutter. The chip has a cylindrical shape with an elliptical bottom surface. In order to suppress the segregation of raw materials, different types of raw materials in which the average size of the major axis, minor axis, and cylindrical height of the ellipsoidal bottom surface is within the range of the chip size ± 20% of the raw material species with the highest usage ratio A chip is preferably used, and the size is more preferably within ± 15%.

In the raw material composition for producing a film, various known additives may be added as necessary in addition to the polyester and the lubricant. Examples of the additive include an antistatic agent; an antiaging agent; an ultraviolet absorber; and a colorant (dye and the like).
The raw material composition is formed into a film by a known method (for example, an extrusion method or a calendar method). The shape of the film is, for example, a flat shape or a tube shape, and is not particularly limited.

In order to impart heat shrinkability to the unstretched film, a stretching process is performed. As the stretching method, for example, a known method such as a roll stretching method, a long gap stretching method, a tenter stretching method, or a tubular stretching method can be employed. In any of these methods, stretching may be performed by sequential biaxial stretching, simultaneous biaxial stretching, uniaxial stretching, and combinations thereof. In the biaxial stretching, stretching in the vertical and horizontal directions may be performed simultaneously, or one of them may be performed first. The draw ratio is preferably in the range of 1.0 to 7.0 times, and the magnification in one predetermined direction (the maximum shrinkage direction) is preferably 3.5 times or more.

In the stretching step, preheating is preferably performed at a temperature not lower than the glass transition temperature (Tg) of the polymer constituting the film and not higher than Tg + 80 ° C., for example. In the heat setting at the time of stretching, for example, it is recommended to pass the heating zone at 30 to 150 ° C. for about 1 to 30 seconds after stretching. Further, after stretching the film, it may be stretched at a predetermined degree before or after heat setting. Further, after the stretching, a step of cooling while applying a stress to the film while keeping the stretched or tensioned state, or a cooling step after releasing the tensioned state may be added following this treatment.

When producing a label from a heat-shrinkable polyester film, it is preferable to perform tube formation with 1,3-dioxolane. It is because sufficient adhesive force is provided. In forming the tube, 1,3-dioxolane may be applied to one surface of the film and the other surface of the film may be pressure-bonded to the coated surface. When the adhesiveness is insufficient, there is a possibility that the label adhesion part may be peeled off when the label is heat-shrinked or when the beverage bottle is handled.

In order to obtain a film label having the above-mentioned dynamic friction coefficient μd, a configuration in which an easy-sliding layer is formed on the outer surface of the film label is preferable. As a method for forming the slippery layer, it is sufficient that the slippery layer can be uniformly formed on the surface of the film. However, the slippery layer coating liquid applied during the film formation process (in-line coating), The method of coating (offline coating) is simple, but in particular the cost and the effect of heat treatment during stretching after coating to improve the adhesion between the coating layer and the film are expected. Is preferred. As a coating method, any known method such as a reverse roll method, an air knife method, or a fountain method can be employed. It is desirable to include a lubricant in the coating solution used for coating.

  It should be noted that the use of a particulate lubricant component as a lubricant may interfere with the transparency of the film and may cause the particles to agglomerate. Preferred lubricants that do not cause such problems include paraffin wax, microwax, polypropylene wax, polyethylene wax, ethylene-acrylic wax, stearic acid, behenic acid, 12-hydroxystearic acid, stearic acid amide, oleic acid amide, Erucic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, ethylene bis oleic acid amide, butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, hydrogenated castor oil, stearyl stearate, siloxane, higher alcohol type Molecule, stearyl alcohol, calcium stearate, zinc stearate, magnesium stearate, lead stearate silicone (dimethylsiloxa ) Based low molecular weight compound (oil) or silicone (dimethylsiloxane) -based resins., These other which may be used alone, or may be used in combination of two or more if necessary. Among these, silicone compounds and silicone resins, particularly copolymer resins containing a silicone component are recommended. This is because the dynamic friction coefficient of the film surface is reduced, the change of the friction coefficient before and after the hot water treatment is small, the solvent adhesiveness of the film is hardly hindered, and the effect of preventing the transfer of the slippery layer is great.

  Here, the silicone type refers to organosiloxanes, which are oily, rubbery, and resinous, and are called silicone oil, silicone rubber, and silicone resin, respectively. Since these all have a water repellent effect, a lubrication effect, a release action, etc., inclusion in the outermost layer portion of the film is effective in reducing the surface friction. In addition, when used as a beverage container label, it is often attached by heat-shrinking using steam or hot air. In a slippery layer with low water resistance, the heat-shrinking treatment using steam causes a decrease in slipperiness. Although it is easy, good slipperiness can be maintained even after the steam treatment due to the water repellent effect inherent in silicone.

  Among the silicone-based resins, a copolymer resin containing a silicone component is particularly preferable, and examples thereof include a silicone / acrylate copolymer. When it is formed on the surface of the polyester film as an easy-sliding layer and then wound into a roll, it has a great effect of making it difficult to transfer to the back surface of the film. Further, when used as a beverage label, the film surface is subjected to a printing process, but the printability is hardly hindered.

  The content of the silicone component is preferably from 10 to 80% by weight, more preferably from 20 to 70%, as the existing amount in the slippery layer. If the content is less than 10% by weight, the effect of improving the slipperiness is small, and if it exceeds 80% by weight, the easy-slip layer component is easily transferred to the back surface when rolled.

In order to suppress the surface resistivity, it is preferable to add an antistatic agent, and such antistatic agents include quaternary ammonium salts, fatty acid polyhydric alcohol esters, polyoxyethylene adducts, betaine salts, Surfactants such as alanine salts, phosphate salts, sulfonates, and polyacrylic acid derivatives are effective.
In particular, sodium alkyl sulfonate is recommended because it has an adverse effect on lubricity in addition to the antistatic effect. A preferable addition amount is preferably in the range of 1 to 70% by weight, particularly preferably in the range of 10 to 60% by weight, as the existing amount in the slipping layer.
Further, the surface resistivity of the easy-sliding layer is preferably 1 × 10 ¹⁴ (Ω / □) or less, more preferably 1 × 10 ¹³ (Ω / □) or less.

A binder resin may be contained in the coating solution. Inclusion of the binder resin is effective in preventing deterioration of printability. With transparent film labels, printing is usually applied to the surface that comes into contact with the container, and especially for the purpose of improving the slipperiness of the beverage container, the easy-slip layer surface is opposite to the surface where the label contacts the container. In many cases, printing is performed on the surface opposite to the slippery layer. Therefore, the printability on the opposite side of the easy-slip layer is important. It is the transfer of the slippery layer that causes the printability on the outer surface side of the film label to be hindered. This occurs when a film having an easy-sliding layer is rolled up and wound, and the easy-sliding layer is partially or entirely transferred to the opposite surface. The binder resin has the effect of preventing this transfer.
Furthermore, the binder resin is effective for maintaining the antistatic effect. Many of those used as an antistatic agent have high water solubility. When a container with an antistatic agent on the surface is placed on the container, and the steam is blown through the inside of a shrinking tunnel (steam tunnel), the antistatic agent flows down by the steam. In addition, sufficient antistatic properties cannot be obtained in the final product (labeled container). The binder resin has an effect of preventing the antistatic agent from flowing down.

  Examples of the resin component include polyester resins, polyamide resins, polyurethane resins, epoxy resins, phenol resins, acrylic resins, polyvinyl acetate resins, polyolefin resins such as polyethylene and polypropylene, and copolymers thereof. Or a modified resin, a cellulose resin, etc. are mentioned. When used as a binder of a silicone component-containing copolymer, if a component similar to the copolymer component is used, the effect as a binder is great. Moreover, since the resin used as the binder in the present invention needs water resistance, it is essential that the resin be essentially water-insoluble.

  Use of water-soluble or water-dispersible lubricants, binder resin components, and antistatic agents is preferable from the viewpoint of safety and environmental friendliness.

The amount of the coating solution, the amount present on the film after stretching is preferably 0.002~0.5g / m ^2, more preferably from 0.005~0.4g / m ^2. If it is less than 0.002 g / m ² , the slipping property will be small, and if it exceeds 0.5 g / m ² , the transparency of the film will be lowered, the solvent adhesion will be lowered, and wear debris will be generated during processing. This is not preferable because it tends to occur and may lead to a decrease in productivity.

In addition, although the thickness of the heat-shrinkable film label of this invention is not specifically limited, For example, as a heat-shrinkable film label for labels, 10-400 micrometers is preferable and 15-300 micrometers is more preferable. More preferably, it is 20-70 micrometers.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are not intended to limit the present invention, and modifications and implementations within the scope of the present invention are included in the present invention. In addition, the measuring method of the physical property of the film obtained by the Example and the comparative example is as follows.

As the measurement sample, a part of the film label that was shrink-fitted to the beverage bottle was cut and removed from the bottle.

(1) Friction coefficient The dynamic friction coefficient μd was measured in an environment of 23 ° C. and 65% RH in accordance with JIS K-7125. In addition, the direction parallel to the periphery when both the fixed side sample and the thread attachment sample were attached to the bottle was defined as the sliding direction.

(2) Surface specific resistance The surface specific resistance was measured with a surface resistor (specific resistance measuring device manufactured by KAWAGUCHI ERECTRIC WORKS) under the conditions of an applied voltage of 500 V, 23 ° C., and 65% RH.

(3) Solvent adhesion 1,3-dioxolane was applied between the non-printing portions of the non-slip layer surface of the label, and the easy-slip layer surface, which is the other surface of the label, was pressure-bonded to this coating surface and bonded. The sample was cut to a width of 15 mm in a direction parallel to the circumference when the sample was attached to the bottle as a label, and a T-type peel test in the above direction of the joint portion was performed in accordance with JIS K 6854 under the condition of a tensile speed of 200 mm / min. went.

Film 1
1) Polyester resin and unstretched film Polyethylene terephthalate 40% by weight, polyester terephthalic acid 100% by mole, neopentyl glycol 30% by mole and ethylene glycol 70% by weight, and polybutylene terephthalate 10% by weight are mixed. The obtained polyester composition was mixed, melt-extruded with a single screw extruder at 280 ° C., and rapidly cooled to obtain an unstretched film having a thickness of 180 μm.

(Preparation of coating solution)
Silicone / acrylic acid ester copolymer aqueous dispersion (Charine NS-626, manufactured by Nissin Chemical Industry Co., Ltd.), 35% by mass of the total solid content of the coating liquid, acrylic acid ester copolymer aqueous dispersion The solid content of the liquid (Vinyl Blanc 2585 Nissin Chemical Industry Co., Ltd.) is 10 mass% in the solid content, the solid content of the acetylene glycol derivative (Surfinol 486 Air Products Japan) is 5 mass% in the solid content, and the antistatic agent (TB214 Matsumoto 100 kg of an aqueous solution containing 50% by mass of oil and fat (manufactured by Oils and Fats Pharmaceuticals) and 20% by mass of isopropyl alcohol was prepared and charged into the tank.

The unstretched film is coated with a coating solution by a fountain die coating / smoothing bar method, and then the coating film is preheated at 100 ° C. for 10 seconds with a tenter, and then stretched 4.0 times at 80 ° C. in the transverse direction. For 10 seconds. The thickness of the film was 45 μm, and the coating amount of the slippery layer was 0.02 g / m ² . The obtained film was named film 1.

Film 2
As for the coating solution, the solid content of the silicone-acrylic acid ester copolymer aqueous dispersion (Charine FE-230, manufactured by Nissin Chemical Industry Co., Ltd.) was 35% by mass in the total solid content of the coating solution, and water of the copolymerized polyester resin. The solid content of the dispersion (AGN709 manufactured by Toyobo) is 10% by mass in the solid content, the solid content of the acetylene glycol derivative (Surfinol 486 manufactured by Air Products Japan) is 5% by mass in the solid content, and the antistatic agent (Bicester CAP-Y Matsumoto). A heat-shrinkable film was obtained in the same manner as the film 1 except that an aqueous liquid containing 50% by mass in solids and 20% by mass of isopropyl alcohol was used as the coating solution. The obtained film was named film 2.

Film 3
Solid content of dimethyl silicone resin (SE4005 manufactured by Nissin Chemical Laboratory) is 35% by mass in the total solid content in the coating liquid, and solid content of aqueous dispersion of copolymerized polyester resin (AGN702 manufactured by Toyobo) is 10% in solid content. %, The solid content of acetylene glycol derivative (Surfinol 486 manufactured by Shin-Etsu Chemical Co., Ltd.) is 5% by mass in the solid content, the antistatic agent (Ansticks HT-100 manufactured by Toho Chemical Co., Ltd.) is 50% by mass in the solid content, and isopropanol 20 A heat-shrinkable film was obtained in the same manner as the film 1 except that an aqueous liquid containing mass% was used as the coating liquid. The obtained film was designated as film 3.

Film 4
As for the coating solution, the solid content of the aqueous dispersion of silicone / acrylate copolymer (Charine FE-230, manufactured by Nissin Chemical Industry Co., Ltd.) is 70% by mass in the total solid content of the coating solution, and water of the copolymerized polyester resin. An aqueous liquid containing 20% by mass of the solid content of the dispersion (manufactured by AGN 709 Toyobo) and 10% by mass of the solid content of the acetylene glycol derivative (Surfinol 486 Air Products Japan) and 20% by mass of isopropyl alcohol. A heat-shrinkable film was obtained in the same manner as for the film 2 except that the coating amount was 0.01 g / m ² . The resulting film was designated as film 4.

Film 5
Regarding the coating solution, a heat-shrinkable film was formed in the same manner as the film 1 except that an antistatic agent (TB214 made by Matsumoto Yushi) and an aqueous solution containing 20% by mass of isopropanol were used as the coating solution and the coating amount was 0.01 g / m ^2. Obtained. The obtained film was designated as film 5.

Film 6
A heat-shrinkable film was obtained in the same manner except that the coating solution was not applied to film 1. The resulting film was designated as film 6.

Film 7
A heat-shrinkable polyester film having a thickness of 45 μm was obtained in the same manner as film 2 except that the coating amount was 0.8 g / m ² . The resulting film was designated as film 7.

Cylindrical labels were prepared with films 1 to 7 such that a coat layer having a height of 180 mm and a circumference of 220 mm was the outer surface.
Using a steam tunnel made by Fuji Astec Inc (model: SH-1500-L), the above label was passed through for 15 seconds, at a first zone temperature of 70 ° C., a second zone temperature of 75 ° C., and a third zone temperature of 82 ° C., and 500 ml It was heat-shrinked and attached to a PET bottle beverage. Table 1 shows the results of clogging evaluation when this label-attached bottle was put into and discharged from a vending machine, and the physical property measurement results of a part of the film label cut and removed from the bottle.

    The heat-shrinkable film label of the present invention is excellent in slipperiness and can prevent clogging in a vending machine when used as a label for bottled beverages, etc., and has excellent antistatic performance due to adhesion of dirt. Appearance deterioration can be prevented. Moreover, it has processing characteristics suitable for cylindrical label processing. Therefore, it is very useful as a label for covering containers such as bottled beverages.

Claims (7)

  A heat-shrinkable polyester film label coated on a container, having an easy-slip layer on the surface and having a coefficient of dynamic friction μd between the outer surfaces of the labels coated on the container of less than 0.30. The surface specific resistance value of at least one surface of the label coated on the container is 1 × 10 ¹⁴ (Ω / □) or less in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%. Heat shrinkable polyester film label. The surface specific resistance value of at least one surface of the label coated on the container is 1 × 10 ¹³ (Ω / □) or less in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%. Heat shrinkable polyester film label.   The heat-shrinkable polyester film label according to any one of claims 1 to 3, wherein the heat-shrinkable polyester film label is covered with a container having a capacity of 1000 ml or less.   The heat-shrinkable polyester film label according to any one of claims 1 to 3, wherein the heat-shrinkable polyester film label is covered with a container having a capacity of 500 ml or less.   The heat-shrinkable polyester film label according to any one of claims 1 to 5, wherein an easy-slip layer containing a silicone-containing component is provided as an outermost layer on at least one surface.   The heat-shrinkable polyester film according to any one of claims 1 to 6, wherein a non-printing portion of the slippery layer surface and the non-slippery layer surface of the label is solvent-bonded with 1,3-dioxolane. label.