JP2001220180A - Returnable glass bottle and producing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a returnable glass bottle which can be produced with a simple operation, moreover is completely protected in a surface thereof by a thin alkali-proof protective film of the order of 50 μm, completely prevents the fragments when the glass bottle bursts from scattering, is durable for repeated washing, is light in weight and has a favorable appearance. SOLUTION: This returnable glass bottle has an alkali-proof and injury resistant cover comprising a heat shrinkable polyolefin film which is stuck via an adhesive layer disposed over the whole part on the surface thereof. This returnable glass bottle is produced in such a manner that the heat shrinkable polyolefin film which has an alkali-proof adhesive layer which is non-sticky at shrinkage temperature or less and is adhesive at a temperature higher than the shrinkage temperature over the whole surface is molded tubularly, subsequently is fitted to the glass bottle, is tightly adhered by heating and shrinkage and, thereafter, the tubular polyolefin film is stuck on the surface of glass bottle to form the alkali-proof and injury resistant cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a returnable glass bottle having a coating that protects the surface and suppresses scattering of shards at the time of rupture, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, various materials have been recycled and reused for the purpose of effective use of resources and reduction of industrial or domestic waste. One of these is a returnable glass bottle that repeatedly collects and uses the glass bottle. On the other hand, a protective coating is applied to the surface of a glass bottle in order to protect the glass bottle from rupture due to an external impact or an increase in internal pressure and to prevent fragments from being scattered at the time of rupture.

[0003] When such a protective coating is applied to a returnable glass bottle, it is required to have alkali resistance and chemical resistance that can withstand repeated washing treatments required for reuse. Until now, returnable glass bottles having such a coating include those coated with ceramics such as SnO ₂ or TiO ₂ at the hot end immediately after glass molding (Japanese Patent Application Laid-Open No. 3-13147), and having a moderate adhesive strength. Having a polymer film made of natural rubber, synthetic rubber or synthetic resin with high elasticity as an inner layer and a polymer material having a high mechanical strength as an outer layer (Japanese Patent Publication No. 50-20964). Publication).

However, immediately after glass molding, SnO ₂
In order to coat the glass surface with ceramics such as TiO ₂ and TiO _2, it is necessary to heat the glass surface to 550 to 700 ° C. and contact the raw material. It has the drawback of causing glare on the surface and disfiguring the appearance, and applying multiple polymer coatings requires complicated operations and special equipment, which inevitably increases the cost and, in addition, increases the cost of coating. Since the film thickness is large (approximately 90 to 150 μm), there is a disadvantage that the usability is deteriorated.

[0005]

SUMMARY OF THE INVENTION The present invention can be manufactured by a simple operation, and its surface is completely protected by a thin alkali-resistant protective film of about 50 .mu.m. It is an object of the present invention to provide a lightweight and good-looking returnable glass bottle in which scattering is completely prevented and which can withstand repeated washing.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on returnable glass bottles having a protective coating on the surface, and as a result, the surface of the returnable glass bottle is provided with an adhesive layer provided over the entire surface. It has been found that the above object can be achieved by applying an alkali-resistant and scratch-resistant coating made of a heat-shrinkable polyolefin-based film, and the present invention has been made based on this finding.

That is, the present invention provides a returnable glass bottle characterized in that it has an alkali-resistant and scratch-resistant coating made of a heat-shrinkable polyolefin film adhered through an adhesive layer provided over the entire surface,
And a heat-shrinkable polyolefin-based film having an alkali-resistant adhesive layer that is non-tacky below the shrinkage temperature and exhibits adhesiveness at higher temperatures over the entire surface in contact with the glass bottle, Is attached to the glass bottle, heated and shrunk to make it adhere to the surface of the glass bottle, and then heated to adhere the cylindrical polyolefin film to the surface of the glass bottle to form an alkali-resistant and scratch-resistant coating. It is intended to provide a method for producing a returnable glass bottle characterized by the following.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The glass used as the material of the returnable glass bottle of the present invention may be any of silicate glass, borate glass and phosphate glass, and is not particularly limited. Na ₂ O-SiO ₂ based glass or Na ₂ O-Ca that is generally used as a glass
Such as O-SiO ₂ system glass. This one is
It may be formed into uncolored bottles such as medicinal bottles, drinking water bottles, juice bottles, etc., or may be formed into colored bottles such as sake bottles, beer bottles, wine bottles and the like.

Next, the coating provided on the surface of the returnable glass bottle of the present invention comprises a heat-shrinkable polyolefin-based film and an adhesive layer provided on the entire surface in contact with the glass. As a material of the heat-shrinkable polyolefin-based film, a polypropylene-based resin having a melting point of 130 ° C. or more is preferable in that it can sufficiently withstand the temperature required for completely bonding the adhesive layer to the glass surface. Here, the polypropylene-based resin means a copolymer containing polypropylene or propylene as a main component and other olefins such as ethylene, butene, pentene, hexene, and heptene as comonomers. In addition, a polyethylene resin, that is, a copolymer mainly composed of polyethylene or ethylene, and a polybutene resin, that is, a copolymer mainly composed of polybutene or butene can also be used. In the alkali resistance test, the polystyrene-based resin becomes cloudy and the polyester-based resin cracks, so that these cannot be used for returnable bottles.

The heat-shrinkable polyolefin film used in the present invention may be a single layer or a multilayer, but has at least a three-layer structure, and the outer layer is made of polypropylene, ethylene-propylene random copolymer, ethylene-butene-propylene copolymer. It is preferable that the intermediate layer be formed of a polypropylene resin having a melting point of 130 ° C. or higher and the polyolefin resin having a melting point of lower than 130 ° C. By forming the intermediate layer with a polyolefin resin having a melting point of less than 130 ° C., the heat shrinkage can be improved. Melting point is 1
Polyolefin resins having a temperature of less than 30 ° C include butene-
Polypropylene resin such as propylene copolymer, low melting point ethylene-butene-propylene copolymer, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, polybutene-based resin, and cyclic olefin-based resin are used. Can be When the outer layer has poor adhesion to the polypropylene resin like the polyethylene resin, an adhesive layer made of a mixture of the polyethylene resin and the polypropylene resin may be further provided between the two.

In the case of a multilayer structure as described above, it is preferable to add a petroleum resin to the intermediate layer in order to improve the shrinkage characteristics. This petroleum resin includes aliphatic hydrocarbons,
There are alicyclic hydrocarbons, hydrogenated hydrocarbons and the like, and these are blended in the range of 1 to 40% by weight.

The heat-shrinkable polyolefin-based film may contain an ultraviolet absorber and a light stabilizer such as a hindered amine compound, if necessary, in order to secure weather resistance.

In the present invention, the thickness of the heat-shrinkable polyolefin film is 20 to 100 μm, especially 40 to 6 μm.
It is preferable to select within the range of 0 μm. If the thickness is smaller than this, it is easy to break or scratch, and the surface protection of the glass bottle,
Sufficient effects such as debris scattering prevention and protection of the printed surface cannot be obtained, and when the thickness is larger than this, the heat shrinkability is impaired. This heat-shrinkable polyolefin-based film must be uniaxially stretched in the transverse direction so that it shrinks in the transverse direction when formed into a cylindrical shape. The draw ratio is 5
A range of 10 to 10 times is appropriate. The heat-shrinkable polyolefin-based film preferably has at least one surface, a surface in contact with the adhesive layer, or a printed surface adjusted to a surface tension of 400 μN / cm or more by a roughening treatment, for example, a corona treatment.

Next, as the adhesive for forming the adhesive layer provided on the surface of the heat-shrinkable polyolefin film in contact with the glass bottle, a polyurethane adhesive having good alkali resistance, acid resistance and alcohol resistance is preferable. . Polyurethane adhesives are usually aqueous solutions or aqueous dispersions thereof,
That is, it is used as a polyurethane emulsion, and this polyurethane emulsion has an anionic charge,
It is composed of an ionic polyurethane emulsion having a cationic charge or a nonionic urethane emulsion having a hydroxyl group.

For the formation of the adhesive layer in the present invention, such a polyurethane emulsion may be used alone, but usually, other polymer emulsions, tackifying resins, thickeners, wetting agents, plasticizers, What mixed and selected organic solvent etc. arbitrarily is used.

The polyurethane emulsion for forming the adhesive layer in the present invention is obtained, for example, by subjecting an aromatic polyester polyol having a carboxyl group and an excess of a polyisocyanate such as hexamethylene diisocyanate to urethane-forming reaction in an organic solvent. , A diamine or the like, followed by neutralization with a low molecular amine, and then adding water to remove the organic solvent by azeotropic distillation. In addition, JP-A-5-97962, JP-A-8-225780, JP-A-8-33
It can also be prepared with reference to the method described in JP 7767.

Further, these polyurethane emulsions can be obtained as commercial products. Such commercial products include Dispacoll U-42 and U-53,
U-54, KA-8481, KA-8584 (above, trade names of Sumitomo Bayer Urethane Co.), Hydran H
W-111, HW-311, HW-333, HW
-337, HW-350, HW-374, AP-
20, same AP-40F, same AP-60LM, same AP-8
0 (trade names of Dainippon Ink and Chemicals, Inc.), Samprene UXA-3005, UXA-306, and UX-3
12 (above, product names of Sanyo Chemical Industries), Superflex 107M, 110, 126, 130, 1
50, 160, 300, 361, 370, 4
10, 420, 460, 700, 760, 8
20 (the above are trade names of Daiichi Kogyo Seiyaku).

Next, these polyurethane emulsions are charged into an aqueous processing pot, and an aqueous dispersion of an acrylic polymer, an aqueous dispersion of a polymer such as an aqueous dispersion of ethylene-vinyl acetate polymer, a tackifying resin such as a rosin ester, polyvinyl alcohol , A wetting agent such as succinic ester, and a high-boiling organic solvent such as adipic diester.

As the above-mentioned polyurethane emulsion, a so-called anionic polyurethane emulsion having an anionic charge in a molecule such as a carboxyl group or a sulfonic acid group is preferable in view of stability during storage and workability. Among them, those having a carboxyl group are most preferable in terms of adhesiveness and reactivity with a crosslinking agent to be used.

The main components of the polyurethane emulsion are one or more polyols selected from polyether polyols, aromatic polyesterols and aliphatic polyesterols as polyols, and fatty acids such as hexamethylene diisocyanate and isophorone diisocyanate as polyisocyanates. It is a polymer obtained by subjecting one or more polyisocyanates selected from aromatic polyisocyanates such as aromatic polyisocyanates, diphenylmethane diisocyanate and toluene diisocyanate to urethane-forming reaction. Among these, the aromatic polyester-ol and the aliphatic polyester-ol as the polyol, and the aromatic polyester-type urethane polymer and the aliphatic polyester-type urethane polymer mainly composed of the aliphatic polyisocyanate as the polyisocyanate have the adhesion to the base film. It is preferable in that it is good. Among them, the most preferable urethane polymer which provides various functions of the present invention is an aromatic polyester type urethane polymer. In particular, an anionic polyurethane emulsion having a carboxyl group is most preferable when the polymer is an aromatic polyester type urethane polymer. Bond CVC880 (manufactured by Konishi Corporation, trade name) is commercially available as an adhesive containing this polyurethane emulsion as a main component.

When the adhesive layer of the present invention is formed, it is preferable to use a mixture of a crosslinking agent such as an epoxy compound, an aziridine compound, a polyisocyanate compound, a carbodiimide compound and an oxazoline compound in the polyurethane emulsion. The amount of the crosslinking agent in this case is
0.1 to 50 parts by weight as a pure component is added to 100 parts by weight of the urethane polymer. The preferred range for providing the functions of the present invention is 0.2 to 30 parts by weight. inside that,
The optimum region in consideration of the thermal adhesion and water resistance is 0.5 to 15 parts by weight.

Specific examples of the crosslinking agent used at this time include bisphenol A type or F type epoxy resin, polyglycidyl ether of polyhydric alcohol, N, N, N, '.
Epoxy compounds such as N'-tetraglycidyl meta-xylylenediamine, polyglycidyl ether of sorbitol EO adduct, 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], diphenylmethane-bis-4 4'-N, N'-
Aziridine compounds such as diethylene urea, toluylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude MDI, hexamethylene diisocyanate (HDI), metaxylene diisocyanate (XDI), polymethylene polyphenyl polyisocyanate, and modified products of the above substances And carbodiimide compounds such as diisopropylcarbodiimide, dicyclohexylcarbodiimide, and polycarbodiimide obtained by a decarbonation condensation reaction of an aromatic diisocyanate. As a commercially available product, UCARNKNK XL-29SE (UnionC
arbid company name), Stabaxol (Rei
nChemie), carbodilite (registered trademark of Nisshinbo) and epocross (trade name of Nippon Shokubai)
There is. Among them, epoxy compounds and carbodiimide compounds are preferred in terms of reactivity and adhesiveness. Among them, the most preferred compound providing the functions of the present invention is a carbodiimide compound.

In order to form the adhesive layer of the present invention, a polyurethane emulsion optionally containing a crosslinking agent is applied to a heat-shrinkable film adherend by gravure printing, screen printing, microgravure, reverse, comma coater or the like. Apply to the surface that will be in contact. The coating amount at this time is 0.3 to 8 g / m ² , preferably 0.5 to 5 g / m ² , and more preferably 1 to 3 g / m ² as a solid content.
Is selected in the range. If the amount is less than this, sufficient adhesive performance cannot be exhibited, and if the amount is too large, not only does the non-adhesion at room temperature be hindered, but also after adhesion to a glass bottle, moisture permeates into the adhesive layer and alkali resistance decreases.

When a print layer is provided on the returnable glass bottle of the present invention, the print layer lacks alkali resistance, acid resistance, and alcohol resistance, so that the print layer is provided between the heat-shrinkable polyolefin film and the adhesive layer. It is necessary.

For returnable bottles, 8
Alkali resistance, pH 3 which does not cause whitening, peeling or shrinking even when immersed in a 4% aqueous sodium hydroxide solution at 0 ° C. for 5 hours.
Acid resistance that does not cause whitening, peeling, or shrinking even when immersed in a hydrochloric acid aqueous solution for 24 hours, and alcohol resistance that does not cause whitening, peeling, or shrinking even when immersed in a mixed solution of 20% ethanol and 80% water for 24 hours. Therefore, when a heat-shrinkable polyolefin-based film is mounted thereon, it is necessary to adopt full-surface bonding so that water does not enter the bonding surface. After the adhesive is applied to the heat-shrinkable polyolefin-based film in this manner, the adhesive is dried usually at a temperature of 60 to 70 ° C. to form an adhesive layer.

The heat shrinkage rate of the heat-shrinkable polyolefin film of the present invention at 100 ° C. is 30% or more in the transverse direction (main shrinkage direction) and 15% or less in the vertical direction (direction perpendicular to the main shrinkage direction). Preferably, it is selected so as to be 40% or more in the horizontal direction and 10% or less in the vertical direction.

[0027]

Next, the present invention will be described in more detail with reference to examples.
In addition, the measurement of the physical property in each example was performed by the following methods.

(1) Heat Shrinkage A 100 m sample was prepared from a heat-shrinkable polyolefin film.
m squared and placed in a glycerin bath at 100 ° C.
After immersion for 0 seconds, it was immediately transferred to cold water, the length L (mm) in the vertical and horizontal directions was measured, and calculated according to the following equation. Heat shrinkage (%) = (100−L) / 100 × 100 = 100−L

(2) Non-adhesive The heat-shrinkable polyolefin film having an adhesive layer is cut into a square of 100 mm to prepare two samples, and the two samples are overlapped so that the adhesive layers face each other. Is left at 40 ° C. for 24 hours while applying a load of 10 g / cm ² from above between the two glass plates. Then
After holding at 23 ° C. for 2 hours, the two films were peeled off,
Evaluation was made according to the following criteria. ：: Peeling without resistance △: Peelable but peelable ×: Adhesive and not peelable

(3) Adhesion A heat-shrinkable polyolefin film cut into a square of 100 mm is bonded to a glass plate via an adhesive layer.
While applying a load of 50 g / cm ² and changing the temperature,
After heating for 0 minutes, cool to 23 ° C. and leave for 2 hours. Then, the film was peeled from the glass plate. The above heating was performed at an interval of 10 ° C. in the range of 60 ° C. to 120 ° C., and the temperature at which the adhesive was not peeled off was determined. ：: Adhesion temperature is 100 ° C. or more △: Adhesion temperature is 80 to 90 ° C. ×: Adhesion temperature is 70 ° C. or less

(4) Alkali Resistance A glass bottle to which a heat-shrinkable polyolefin film is adhered is heated to 70 ° C. in an alkaline aqueous solution containing 2% by weight of sodium hydroxide and 0.2% by weight of sodium gluconate. After immersion for a minute, take out, wash with water, and observe whether there is any abnormality in the film appearance. This operation is repeated, and the number of evaluations until the abnormality is recognized is evaluated.

(5) Alcohol Resistance A glass bottle to which a heat-shrinkable polyolefin film is bonded is immersed in a 50% ethyl alcohol aqueous solution kept at room temperature (20 ° C.), and no abnormality is found in the film after 24 hours. The case was regarded as pass, and the case where any abnormality was recognized was rejected.

(6) Weather resistance The glass bottle to which the heat-shrinkable polyolefin-based film was bonded was exposed to ultraviolet light and water spray using a weathero sunshine meter, and after 300 hours, the appearance was observed. If not, the test was passed, and if any abnormality was found, the test was rejected.

(7) Scratch resistance 25 glass bottles to which a heat-shrinkable polyolefin-based film has been adhered are set on a line simulator (manufactured by AGR), and 30 trips (wet for 30 minutes) in a wet state
When the film was damaged and no damage occurred on the film surface, it was judged as pass, and when any damage occurred, it was judged as reject.

(8) Evaluation for practical use The glass bottle to which the heat-shrinkable polyolefin film was adhered was immersed in the alkaline aqueous solution used in the above-mentioned alkali resistance test for 10 minutes, then the surface was washed with water, and a line simulator (AGR) Manufactured for 1 minute, and the presence or absence of abnormality on the outer surface was observed. This alkali resistance test and the damage test with a line simulator were repeated 15 times, and those with no abnormality were passed, and those with some abnormality were rejected.

REFERENCE EXAMPLE 1 A resin composition mainly composed of a polypropylene copolymer resin constituting an intermediate layer is an ethylene-propylene random copolymer containing 4.6 mol% of ethylene (melting point: 135 ° C.)
38% by weight, 38% by weight of a butene-propylene random copolymer having a butene content of 22.7 mol% (melting point 128 ° C.), a polybutene resin (trade name “Toughmer M-2, manufactured by Mitsui Chemicals, Inc.)
481 ”, melting point 75 ° C) 4% by weight, petroleum resin (Arakawa Chemical Co., trade name“ Alcon P-140 ”, melting point 140 ° C)
20% by weight of the above ethylene-propylene random copolymer as both surface layers, and a benzotriazole-based ultraviolet absorber (trade name “Biosorb 5” manufactured by Kyodo Yakuhin Co., Ltd.)
50 ") is added to the surface layer at 0.05% by weight and to the intermediate layer at 0.3% by weight. Each of these resin compositions is extruded from a separate extruder at 200 ° C. from a T-die into three layers, cooled and solidified by a cooling roll at 40 ° C., and then cooled to 60 ° C.
In the tenter, the film was stretched 8 times in the transverse direction, and subsequently annealed at 55 ° C. for 5 seconds while relaxing 8% in the transverse direction in the tenter to obtain a heat-shrinkable olefin-based film having a thickness of 50 μm (thickness of each layer). The size is 5 μm / 40 μm / 5 μm). Next, one side of this film was subjected to corona treatment. The surface tension of the treated surface was 430 μN / cm. After normal printing was performed on the corona-treated surface of this film, a urethane-based emulsion (manufactured by Konishi Co., Ltd., trade name "Bond C") was applied to the printed surface.
VC880 ") and 10 parts by weight of a carbodiimide-based crosslinking agent (manufactured by Konishi Co., trade name" crosslinking agent D ") and a leveling agent (manufactured by Asahi Glass Co., Ltd., trade name" Surflon 14 ")
1)) The adhesive solution mixed by adding 0.2 parts by weight was applied with a gravure roll (plate depth 32 μ, 180 mesh),
After drying at 60 ° C., a heat-shrinkable olefin film with an adhesive was obtained. The amount of the adhesive applied is 1.5 g / m2 as a solid content.
^{Was 2} . Table 1 shows the physical properties of this film.

REFERENCE EXAMPLE 2 In Reference Example 1, a urethane emulsion (trade name "Bond CVC" manufactured by Konishi Co., Ltd.) having a formulation of an adhesive solution to be applied was used.
880 ”) 100 parts by weight of a polyester emulsion (trade name“ Fine-Tex ES-2200 ”manufactured by Dainippon Ink and Chemicals, Inc.) was used in place of 100 parts by weight. A heat-shrinkable olefin film was obtained. The application amount of the adhesive was 1.5 g / m ² as a solid content. Table 1 shows the physical properties of this film.

REFERENCE EXAMPLE 3 In Reference Example 1, a urethane emulsion (trade name: “Bond CVC” manufactured by Konishi Co., Ltd.) having a formulation of an adhesive solution to be applied was used.
880 ") Acrylic adhesive emulsion (manufactured by Konishi, trade name" Bond CE560 ") 1 instead of 100 parts by weight
A heat-shrinkable olefin film with an adhesive was obtained in the same manner as in Reference Example 1 except that 00 parts by weight was used. The application amount of the adhesive was 1.6 g / m ² as a solid content. Table 1 shows the physical properties of this film.

REFERENCE EXAMPLE 4 In Reference Example 1, a urethane emulsion (trade name: “Bond CVC” manufactured by Konishi Co., Ltd.) of the formulation of the adhesive solution to be applied was used.
880 ") with an adhesive in the same manner as in Reference Example 1 except that 100 parts by weight of EVA-based emulsion (manufactured by Chuo Rika Kogyo Co., Ltd., trade name" Lica Bond Aquatex EC-3200 ") was used instead of 100 parts by weight. A heat-shrinkable olefin film was obtained. 1.5 g of solid adhesive
/ M ² . Table 1 shows the physical properties of this film.

[0040]

[Table 1]

Example 1 The heat-shrinkable polyolefin film with an adhesive obtained in Reference Example 1 having a diameter of 58.2 with the adhesive layer inside.
mm and a height (cut length) of 100 mm into a cylindrical shape, which is formed into an outer diameter of 5 mm using a conventional heat shrink film mounting line.
It was fitted to the body of a glass milk bottle having a size of 6.6 mm and a height (total length) of 140 mm, and was mounted at a heat shrink temperature (surface temperature of the film) of 90 ° C. Table 2 shows the glass bottle mounting properties at this time. Then, the above glass bottle was placed
Heat treatment was performed for 0 minutes to completely adhere the heat-shrinkable polyolefin film to the surface of the glass bottle. About the returnable glass milk bottle obtained in this way, alkali resistance test, acid resistance test, alcohol resistance test, weather resistance test,
A scratch resistance test and a practical application evaluation test were performed. Table 2 shows the results.

Comparative Examples 1 to 3 The heat-shrinkable polyolefin-based film with an adhesive obtained in Reference Examples 2 to 4 was adhered to a glass milk bottle in the same manner as in Example 1. About the returnable glass milk bottle thus obtained, the same test as in the example was performed.
The results are shown in Table 2 as Comparative Examples 1 to 3.

[0043]

[Table 2]

[0044]

According to the present invention, there is provided a returnable glass bottle which has a thin protective coating on the surface and which does not lose its coating even after repeated collection and reuse at least 10 times.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B65D 23/08 C03C 17/34 A C03C 17/34 B65D 1/00 BC (72) Inventor Shoichi Saya Chuo-ku, Tokyo 1-18-1 Kyobashi CHI Kasei Corporation (72) Inventor Naoki 1-18-1 Kyobashi 1-chome Kyobashi, Chuo-ku, Tokyo F-term (reference) 3E033 BA01 BA14 BB08 CA13 3E062 AA09 AC06 JA01 JA08 JB05 JC02 JC06 JD06 JD08 4F100 AG00B AK03A AK07A AK51G BA02 CA02G CB02 DA01 EC182 EJ37A EJ422 GB16 JA03A JB01A JK16A JL00 4G059 AA04 AB01 AC17 FA14 FA17 FB08 GA01 GA11

Claims (6)

[Claims] 1. A returnable glass bottle having an alkali-resistant and scratch-resistant coating made of a heat-shrinkable polyolefin-based film adhered through an adhesive layer provided over the entire surface. 2. The returnable glass bottle according to claim 1, wherein the heat-shrinkable polyolefin-based film is a uniaxially stretched polypropylene-based film. 3. The returnable glass bottle according to claim 1, wherein the adhesive layer comprises a polyurethane resin adhesive containing a crosslinking agent. 4. A heat-shrinkable polyolefin-based film having an alkali-resistant adhesive layer that is non-tacky below the shrinkage temperature and exhibits adhesiveness at higher temperatures over the entire surface in contact with the glass bottle. Then, it is mounted on a glass bottle, heated and shrunk to make it adhere to the surface of the glass bottle, and then further heated to adhere the cylindrical polyolefin-based film to the surface of the glass bottle. Forming a returnable glass bottle. 5. The method for producing a returnable glass bottle according to claim 4, wherein the heat-shrinkable polyolefin-based film is a uniaxially stretched polypropylene-based film. 6. The method for producing a returnable glass bottle according to claim 4, wherein the alkali-resistant adhesive layer comprises a polyurethane-based resin adhesive containing a crosslinking agent.