JP2001341238A - Stretch film with anti-corrosive function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film with anti-corrosive function by using which two processes consisting of packaging with an anti-corrosive paper and packaging with a film made of a synthetic resin to prevent moisture from penetrating are not required or two processes consisting of coating a metal surface with a rustproof oil and packaging with the film made of a synthetic resin are not required or a process in which an article to be packed is placed in a tubular film made of a synthetic resin coated with a vaporizable rustproof agent not to make packaging of a large-sized article to be packaged difficult. SOLUTION: An anti-corrosive stretch film with anti-corrosive function comprises a anti-corrosive layer (A) consisting of a resin composition containing the vaporizable rustproof agent and a pressure-sensitive adhesive layer (B) consisting of a resin composition containing a pressure-sensitive adhesive is provided. It is therefore suitable for a stretch film for packaging a metal product for which rust is prevented from being generated which is excellent adhesive properties between films each other and can hermetically seal the article to be packaged and has anti-corrosive function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film used for packing products requiring rust prevention, particularly metal products.

[0002]

2. Description of the Related Art Conventionally, when rust-preventive packaging is performed on metal products that need to be prevented from rusting during storage or transportation, after packing with a paper impregnated with a vaporizable rust-preventive agent, ,
In addition, in order to prevent moisture intrusion, dissipation of the rust inhibitor, tearing of rust prevention paper, etc., packing with a synthetic resin film, or applying rust prevention oil on the metal surface and then using a synthetic resin film If the size of the packaged item is relatively small, knead and mix a vaporizable rust inhibitor, or put the packaged item in a coated synthetic resin tubular film and heat seal it. Such methods as sealing are performed.

[0003]

In the case of packing using rust-proof paper, mere wrapping with rust-proof paper causes moisture to enter and rust. It requires two steps of packing with a film and preventing moisture from entering. For this reason, the packing device is large, complicated, and expensive.

[0004] When unpacking and discarding packing materials,
Since two kinds of waste materials, paper and synthetic resin film, are generated, the amount of waste increases. In some cases, it may be necessary to separate paper and synthetic resin.

[0005] When rust-preventive oil is applied to a metal surface and then wrapped in a synthetic resin film, two steps of coating rust-preventive oil and wrapping with a synthetic resin film are required. It is necessary to remove the applied rust-preventive oil before using the metal product which has been used.

[0006] In a method in which an article to be packaged is put into a tubular film made of a synthetic resin to which a vaporizable rust inhibitor has been kneaded or applied, and then sealed by heat sealing, packaging is performed for a large article to be packaged. In addition, the diameter of the tube must be changed according to the size of the object to be packed, and the change in the size of the object to be packed cannot be promptly dealt with.

[0007]

As a result of intensive studies on solving the problems in the prior art as described above, the present invention has found that a rust-preventive layer (A) made of a resin composition containing a vaporizable rust-preventive agent is provided. A laminate comprising at least two pressure-sensitive adhesive layers (B) made of a resin composition containing a pressure-sensitive adhesive, and a metal product that requires rust prevention as a stretch film having a rust-preventive effect to solve these problems Was found to be efficient and effective for packaging.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The rust-preventive stretch film of the present invention is composed of at least two layers, a rust-preventive layer (A) and an adhesive layer (B), and the ratio of the layer thickness is not particularly limited. Ratio (rust prevention layer (A) / adhesive layer (B)) is 10
/ 1 to 1/10, more preferably 5/1 to 1/5. The rust-preventive layer (A) has a surface rust-preventive layer (A1) that is responsible for the initial rust-preventive performance and an internal rust-preventive layer (A) that is responsible for the sustained rust-preventive effect.
2) Two layers can be provided. The ratio of the layer thickness in this case is not particularly limited, but preferably, the layer thickness ratio (surface rust preventive layer (A1) / internal rust preventive layer (A2)) is 5/1 to 1/5.
Range.

The material of the rust-preventive stretch film of the present invention can be a synthetic resin such as a polyethylene resin or a polypropylene resin, and is not particularly limited.
It is preferable to use an ethylene / α-olefin copolymer, and ethylene / α having a density of 0.890 to 0.920 g / cm ³ and a flexural rigidity of 800 to 2000 kg / cm ^2.
-It is preferred to use olefin copolymers. Density less than 0.890 g / cm ³ or flexural rigidity 800 kg /
If it is less than cm ² , the strength of the film decreases and the density becomes 0.92.
If the flexural rigidity exceeds 0 g / cm ³ or the flexural rigidity exceeds 2000 kg / cm ² , the film becomes hard and the adhesion is impaired. Adhesive layer (B)
It is preferable to use an ethylene / vinyl acetate copolymer.

As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer of the rust-preventive stretch film of the present invention, one or more kinds of liquid aliphatic hydrocarbon resins, terpene resins, cumarone-indene resins, petroleum resins and the like are mixed. Although it is not particularly limited, it is preferable to use a liquid aliphatic hydrocarbon resin.

The rust preventive used in the present invention is a mixture of one or more of amine salts of organic carboxylic acids, amine salts of nitrite, amine salts of phosphoric acid, amine carbonate, benzotriazole derivatives, heterocyclic amines and the like. Although it is not particularly limited, an appropriate material is used depending on the type of the metal to be packaged.

Since the rustproof stretch film of the present invention may be used outdoors, an ultraviolet absorber, a weatherproofing agent, etc. may be added as necessary.

[0013]

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

The evaluation method is as follows.

(1) Breaking strength, breaking elongation According to JIS Z1702 (dumbbell-shaped test piece, test speed 500 mm / min), using an autograph manufactured by Shimadzu Corporation at a temperature of 23 ° C. and a humidity of 50%. Measured (piercing test, adhesion was also measured at a temperature of 23 ° C and a humidity of 50
% Environment).

(2) Puncture Strength A 10 cm × 10 cm film was measured using an impact tester manufactured by Toyo Seiki Seisakusho (material of impact head: aluminum, diameter: 25.4 mm).

(3) Adhesion Two films of 10 cm × 10 cm (area of 100 cm ² ) are superposed on each other in a direction in which the adhesive layer and the rust-preventive layer are in contact with each other, and no load is applied by a 1.6 kg rubber roller. Using only its own weight, reciprocating and pressing 3 times, temperature 23
After standing at 50 ° C. and a humidity of 50% for 24 hours, the film was vertically peeled off using an autograph manufactured by Shimadzu Corporation, and the load at that time was regarded as adhesive.

(4) Rust prevention test Wet cycle test: A cold-rolled steel sheet which was cut into 200 × 100 mm, heat-sealed into a 80 × 80 mm bag, and washed with ethanol and petroleum benzene as metal test pieces. (25 × 50 × 2 mm) or galvanized steel plate (25 × 50 × 0.8 mm), heat-sealed and sealed, and used as a test specimen. Test specimen at temperature 4
The test pieces were placed in a wet cycle of 16 hours in a wet bath at 9 ° C. and a humidity of 95% or more and left at room temperature for 8 hours, and the test pieces were observed for discoloration and rusting. Evaluation ：: The period until rusting is 8 cycles or more. Δ: The period until rusting is 5 to 8 cycles. X: The period until rusting is 5 cycles or less.

(5) Packaging Suitability Using a coil automatic film packing machine “Coil Wrapper” manufactured by Shineitec Co., Ltd.
(75 mm, width 1050 mm) was wrapped, and the presence or absence of film breakage at the time of wrapping, the presence or absence of a hole in a sharp portion of the coil end face, and the adhesion of the film were observed. If the film breaks, it will not be possible to pack it, which will hinder the packing operation. If a hole is formed in the film, moisture will enter through the hole, resulting in rusting of the package inside. If they are not tightly adhered, the sealed state cannot be maintained, so that moisture enters from there and rusts the packaged items inside. In addition, when the film is cut open with a cutter or the like and opened, it takes time to collect the used film because the film is separated.

Evaluation: Presence or absence of film breakage Whether the film breaks before one coil is completely wrapped. ：: Packaging can be performed without breaking the film. X: The film breaks partly or over the entire width during packaging. -Perforation Is there any perforation in the film that comes into contact with sharp points on the coil end surface after packaging? ：: No perforation occurred. Δ: Does not penetrate the film, but has scratches. X: A hole penetrating the film is formed.・ Adhesiveness Whether the films after packaging are tightly adhered to each other, and whether the film can be kept in close contact when unveiled. ：: The films after packaging are tightly adhered to each other, and when the film is opened, the film is kept in close contact. Δ: The films after packaging are firmly adhered to each other, but the films are separated when unveiled. ×: Films after packaging do not adhere to each other to form a gap.

[0021]

Example 1 An ethylene / α-olefin copolymer (Sumikacene EFV20 manufactured by Sumitomo Chemical Co., Ltd.) was used for the rust preventive layer (A).
3: MFR = 2.0 g / 10 min, density = 0.912 g /
cm ³ , flexural rigidity = 1000 kg / cm ² ) 97 parts by weight, vaporizable rust inhibitor (VCI-1 manufactured by CORTEC Co.)
26) Using a resin composition consisting of 3.0 parts by weight, (B)
An ethylene / vinyl acetate copolymer (Evatate H2081 manufactured by Sumitomo Chemical Co., Ltd .; MFR = 2.0 g / 10
Min, density = 0.93 g / cm ³ , vinyl acetate content 15
%) Using a resin composition consisting of 92 parts by weight and 8 parts by weight of liquid polyisobutylene (Nippon Oil Co., Ltd. Nisseki Polybutene HV-50) as adhesives, each having a diameter of 50 mm,
The mixture was melt-kneaded with an extruder having an L / D of 32, and a co-extrusion inflation method was used to prepare a two-layer film having a total thickness of 50 μm and a thickness ratio of each layer (rust preventive layer / adhesive layer) of 4/1.

[0022]

EXAMPLE 2 An ethylene / α-olefin copolymer (Sumikacene EFV2 manufactured by Sumitomo Chemical Co., Ltd.) was used for the surface rust preventive layer (A1).
03; MFR = 2.0 g / 10 min, density = 0.912 g
/ Cm ³ , flexural rigidity = 1000 kg / cm ² ) 98 parts by weight, vaporizable rust inhibitor (VCI-12 manufactured by CORTEC Co.)
6) Using a resin composition consisting of 2.0 parts by weight, an ethylene / α-olefin copolymer (Sumikasen EFV201 manufactured by Sumitomo Chemical Co., Ltd .; MFR = 1.
5 g / 10 min, density = 0.915 g / cm ³ , flexural rigidity = 2000 kg / cm ² ) 96 parts by weight, 4.0 parts by weight of a vaporizable rust preventive, ethylene / vinyl acetate copolymer on the adhesive layer (B) Combined (Evatate H2081 manufactured by Sumitomo Chemical Co., Ltd .; MF
R = 2.0 g / 10 min, density = 0.93 g / cm ³ , vinyl acetate content 15%) 92 parts by weight, liquid polyisobutylene as an adhesive (Nippon Oil Co., Ltd. Nisseki Polybutene HV-5)
0) Using a resin composition consisting of 8 parts by weight, each was melt-kneaded with an extruder having a diameter of 50 mm and an L / D of 32, and the total layer thickness was 60 μm by the co-extrusion inflation method, and each layer thickness ratio (surface rust prevention) Layer / internal rust prevention layer / adhesive layer) 1/3 / 1-3
A layer of film was made.

Comparative Example 1 An ethylene / α-olefin copolymer (Sumikasen EFV102 manufactured by Sumitomo Chemical Co., Ltd .; MFR) was used for the inner rust preventive layer (A2).
= 1.0 g / 10 min, density = 0.930 g / cm ³ , flexural rigidity = 3600 kg / cm ² ) 98 parts by weight, and a resin composition comprising 2.0 parts by weight of a vaporizable rust inhibitor was used. A three-layer film was formed in the same manner as in Example 2.

Comparative Example 2 An ethylene / α-olefin copolymer (Sumikasen EFV102; MFR, manufactured by Sumitomo Chemical Co., Ltd.) was applied to the surface rust preventive layer (A1).
= 1.0 g / 10 min, density = 0.930 g / cm ³ , flexural rigidity = 3600 kg / cm ² ) 98 parts by weight, and a resin composition comprising 2.0 parts by weight of a vaporizable rust inhibitor was used. A three-layer film was formed in the same manner as in Example 2.

Comparative Example 3 Ethylene / α-olefin copolymer (Sumikacene EFV102 manufactured by Sumitomo Chemical Co., Ltd .; MFR = 1.
Example 1 except that a resin composition consisting of 98 parts by weight of 0 g / 10 min, density = 0.930 g / cm ³ , flexural rigidity = 3600 kg / cm ² ) and 2.0 parts by weight of a vaporizable rust inhibitor was used.
A two-layer film was prepared in the same manner as described above.

[0026]

[Table 1]

[0027]

The rust-preventive stretch film of the present invention is characterized by having excellent adhesion between the films, being capable of sealing a packaged object, and having a rust-preventive function. In addition, it has an excellent balance of mechanical properties, flexibility, piercing strength, and the like excellent in packaging suitability in an automatic packaging machine. The rust-preventive stretch film of the present invention is suitable as a stretch film for packaging metal products that need to prevent the generation of rust.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C23F 11/00 C23F 11/00 GF Term (Reference) 3E086 AD17 BA04 BA15 BA35 BB12 DA08 4F071 AA15 AA19 AA82 AB22 AC12 AE22 AF14Y AH19 BA01 BB06 BC01 BC12 4F100 AH02C AH03C AH07C AK01A AK01C AK09H AK62A AK68B AR00B BA02 BA03 BA07 BA10A BA10B BA25 CA10A CA14C CA16B EH202 GB15 JA13A JB02A JB02C JK04A JK08 JK13 JK17 JL11B YY00 YY00A 4J002 BB051 EN006 FD20 FD206 4K062 AA05 AA08 BB01 BB12 BB16

Claims (6)

[Claims] 1. A rust preventive layer comprising at least two layers of a rust preventive layer (A) made of a resin composition containing a vaporizable rust preventive agent and an adhesive layer (B) made of a resin composition containing an adhesive. Rustproof stretch film with performance. 2. A rust preventive layer (A) comprising two layers, a surface rust preventive layer (A1) having an initial rust preventive effect and an internal rust preventive layer (A2) having a sustained rust preventive effect. The rust-preventive stretch film according to claim 1, comprising three layers (B) and (B). 3. A density of 0.890 to 0.920 g / cm, comprising ethylene and an α-olefin having 4 to 12 carbon atoms.
^{3. An} ethylene-vinyl acetate copolymer resin comprising an ethylene / α-olefin copolymer having a flexural rigidity of 800 to 2000 kg / cm ² as a rust preventive layer (A) and containing a liquid aliphatic hydrocarbon as an adhesive. The rustproof stretch film according to claim 1, further comprising an adhesive layer (B) comprising: 4. The method according to claim 1, wherein the composition is formed by coextrusion.
4. The rust-preventive stretch film according to any one of items 1 to 3. 5. The rust-preventive stretch film according to claim 1, which has a thickness of 30 μ to 200 μ. 6. The vaporizable rust inhibitor comprises one or a mixture of two or more of amine salts of organic carboxylic acids, amine salts of nitrite, amine salts of phosphoric acid, amine carbonates and heterocyclic amines. 6. The rust-preventive stretch film according to any one of items 1 to 5.