JP6432400B2 - Antirust film and antirust film bag - Google Patents

Description

  The present invention relates to a rust preventive film for packaging metal products, which is used to control that the surfaces of various metal materials are oxidized and rusted, and further, by making the rust preventive film into a bag. The present invention relates to a rust-preventing film bag containing a metal product.

  While storing and transporting steel materials or parts and products made of non-ferrous metals such as copper, aluminum and galvanizing, the surface of the metal products is oxidized by oxygen and moisture in the air, and the appearance of the products In addition to reducing value, it can also cause functional problems. In order to avoid such problems caused by rust, rust preventive oil is applied to the surface of metal products, the metal products are packaged with a film and a vaporizable rust preventive tablet is enclosed, and rust-proof paper and Packaging with a rust film is generally performed.

  Of these, the rust-proof film is translucent, so the contents can be recognized, the film has a high waterproof / moisture-proof effect, and there is little dust generation such as paper dust. ing.

  As such a rust preventive film, there is a multilayer rust preventive film characterized by comprising a polyolefin resin layer containing nitrite and a polyolefin resin layer containing an ammonia compound and / or a urea compound (Patent Document 1). ). Although this rust-proof film can exhibit a high rust-preventive effect, it is necessary to add a large amount of rust-preventive components because of the decomposition and reaction of the rust-preventive components.

  In addition, a metallized packaging film in which a water-soluble glass powder and a vaporizable rust preventive such as dicyclohexylamine benzoate are contained in a thermoplastic resin has been proposed (Patent Document 2). However, there is a problem that the glass powder falls off from the film and contaminates the metal product contained therein.

  A polyolefin-based anticorrosive film containing an amine carboxylate and an aromatic carboxylate has been proposed (Patent Document 3), but exhibits an excellent antirust effect against zinc, but against other metals There is a problem that the rust prevention effect is not sufficient.

  Furthermore, a rust-proof film for metal packaging containing p-nitrobenzoic acid and a thermoplastic resin is disclosed (Patent Document 4). However, the rust prevention performance as vaporization is not sufficient, and it is difficult to obtain a stable rust prevention effect.

Japanese Unexamined Patent Publication No. 01-210340 Japanese Patent Laid-Open No. 11-71471 JP 2007-269861 A JP 2008-121070 A

  On the other hand, GHS (The Globally Harmonized System of Classification and Labeling of Chemicals) is an international classification of chemical hazards and labels, and safety data sheets (SDS). The system was harmonized and considered by the United Nations (GHS) GHS subcommittee, formulated as a UN GHS document in 2002, and published in 2003.

  The CLP Regulation (Regulation on Classification, Labeling and Packaging of Substances and Mixtures), which came into effect on January 20, 2009 in Europe, is a regulation on the classification, labeling, and packaging of chemicals in the EU. Introducing GHS into the classification, packaging and labeling system (Directive 67/548 / EEC, Directive 1999/45 / EC), including the classification and labeling inventory introduced under the REACH regulation. It is necessary to label information such as hazards about the judged substance or mixture.

  Sodium nitrite is listed as a hazardous substance in the CLP regulations. Rust-proof paper and rust-proof film using sodium nitrite as a rust-proofing agent correspond to molded products, but are considered to be “intentional releases” in the REACH regulations because of their rust-proof performance due to vaporization. Therefore, there is an idea that the rust preventive paper and the rust preventive film containing sodium nitrite need to be labeled according to the CLP rule even in the molded product. The label may be attached to the exterior of the product, but in order to thoroughly communicate information to workers, end users, etc., labeling on rust-proof paper or the rust-proof film itself should be considered. There is also an opinion.

  For anti-corrosion paper, we introduced a method for describing label information by endless printing on the back of anti-corrosion paper as a means of transmitting label information such as hazards. On the other hand, the rust-proof film is often used as a bag, and in normal endless printing, there is a risk of printing defects and print peeling due to rubbing in physical distribution or the like.

  The present invention provides a rust-proof film and a rust-proof film bag that have excellent rust-proofing effects, the contents can be visually recognized from the outside, and label information such as hazards based on UN-recommended GHS is printed. To do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor performs pitch printing with a design corresponding to the size of the bag with a single-layer or multilayer film containing sodium nitrite as a rust inhibitor. Thus, the present inventors have found that label information such as hazards based on UN GHS can be displayed on each rust-proof film bag without any loss, and the present invention has been completed.

  Further, the present invention will be described in detail below.

The present invention
Item 1. A rust preventive film comprising a polyolefin resin and a rust preventive agent, wherein the rust preventive agent contains sodium nitrite, and the content of sodium nitrite in the total amount of the film is more than 0.3% by weight and less than 5% by weight. The present invention relates to a rust prevention film characterized in that label information based on GHS recommended by the United Nations is displayed by printing.

Furthermore, the present invention provides
Item 2. The printing process surface of a film is related with the antirust film of claim | item 1 whose wetting tension | tensile_strength is 40 mN / m or more by the surface treatment before a printing process.

The present invention
Item 3. The anticorrosive film according to Item 1 or 2, wherein the anticorrosive film has a multilayer structure, the innermost layer on the film side where the metal is wrapped and contacted contains an antirust agent, and the outermost layer does not contain an antirust agent. It relates to film.

The present invention
Item 4. Item 4. The rustproof film according to any one of Items 1 to 3, wherein the thickness of the film layer containing sodium nitrite is 20 μm or more and 100 μm or less.

The present invention
A rust-proof film bag produced by heat sealing and cutting from the rust-proof film according to any one of Items 1 to 4, wherein the seal cut pitch is a multiple of the pitch (cycle) of the print design, The present invention relates to a rust prevention film bag characterized by displaying at least one label information based on UN GHS by printing.

  According to the present invention, a rust prevention film and a rust prevention film bag having excellent rust prevention effect, contents visible from the outside, and clearly and firmly printed label information such as hazards based on UN GHS are obtained. It becomes possible.

It is a printing design of the antirust film bag printed in Examples 1-5.

  As polyolefin resin which can be used by this invention, a polyethylene resin and a polypropylene resin can be used conveniently. As the polyethylene resin, low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene are preferably used. Among these, low-density polyethylene that is excellent in inflation film-forming suitability and heat-fusible is often used.

  As the polypropylene resin, any of a random type and a block type which are a copolymer with a homotype and an ethylene monomer can be used. The polyethylene resin and the polypropylene resin can be used alone or in combination of two or more.

  Various additives can be further blended with these polyolefin resins. Examples of the additive include an antioxidant, a flame retardant, a slip agent, an antiblocking agent, a dispersant, and a light stabilizer.

The rust preventive agent used in the present invention is characterized by containing sodium nitrite. Sodium nitrite itself is not a volatile, hydrolysis occurs due to the presence of moisture or carbon dioxide in the atmosphere, NO2 exhibits excellent anticorrosive performance against a steel material ^- gassing, A rust preventive film is formed on the metal surface. As the rust inhibitor, sodium nitrite can be used alone, but it can also be used as a mixture in combination with other rust inhibitors. Examples of rust preventives that can be used in combination with sodium nitrite in the present invention include nitrites, amine compounds, urea compounds, benzotriazole compounds, fatty acid compounds and salts thereof, aromatic fatty acid compounds and salts thereof, and the like. Can be mentioned.

  Examples of the nitrite include potassium nitrite, calcium nitrite, and magnesium nitrite. Examples of the amine compound include dicyclohexylamine, monoethanolamine, diethanolamine, diisopropylamine, cyclohexylamine, nitronaphthaleneamine and the like. Examples of urea compounds include urea and thiourea. Examples of the benzotriazole compound include 1,2,3-benzotriazole, 4-methyl-1,2,3-benzotriazole, and 5-methyl-1,2,3-benzotriazole. Examples of the fatty acid compound include lauric acid, mytilic acid, palmitic acid, stearic acid, and dicarboxylic acids such as succinic acid, adipic acid, suberic acid, brassic acid, and sebacic acid. Examples of the aromatic fatty acid include benzoic acid, toluic acid, dimethylbenzoic acid, terephthalic acid and the like. As the fatty acid salt, metal ions such as sodium, potassium and calcium, or ammonium ions are used as counter ions.

  The blending amount of the rust inhibitor is more preferably 0.3% by weight or more and 10% by weight or less with respect to the total weight of the film. If the blending amount of the rust inhibitor exceeds 10% by weight, the rust preventive effect is not improved, and the rust preventive agent floats on the film surface and falls off, which may cause contamination of the metal product. On the other hand, if it is less than 0.3% by weight, the rust prevention performance cannot be sufficiently exhibited.

  The method of kneading the rust inhibitor with the polyolefin resin is not particularly limited, but a general kneader can be used. As the kneader, a single screw extruder, a twin screw extruder, a Banbury kneader, a roll kneader, an intensive mixer, and the like can be suitably used. It is common to produce a master batch in which the blending amount of the rust inhibitor during kneading is greater than the blending amount during film forming. As a compounding quantity of the rust preventive agent in a masterbatch, it is preferable that it is 5 to 50 weight%. If it exceeds 50% by weight, the fluidity of the resin decreases, which is not preferable. On the other hand, if it is less than 5% by weight, the productivity decreases, which is not preferable.

  As a method for forming a polyolefin resin film, a melt extrusion method such as an inflation method or a T-die casting method is preferably used. The rust-proof film can be a single layer, but can also be a multilayer film having a structure in which a plurality of film layers are laminated by using a multilayer die. When the rust preventive film has a multilayer structure, the outermost layer does not contain a rust preventive agent, so that the printability on the film surface can be improved and unnecessary contamination can be prevented. Is also preferable. Furthermore, since it is possible not to use an unnecessary rust preventive component, it is economically preferable.

  The rust-proof film in the present invention is preferably 20 μm or more and 150 μm or less in the thickness of the whole film regardless of whether it is used in a single layer or multiple layers. Preferably, they are 30 micrometers or more and 120 micrometers or less, More preferably, they are 40 micrometers or more and 100 micrometers or less. If the thickness is less than 20 μm, the rust prevention performance is lowered, and sufficient film strength may not be obtained. On the other hand, when the thickness is 150 μm or more, there is no improvement in rust prevention performance, transparency is lowered and visibility is deteriorated.

  Moreover, it is preferable that the thickness of the film layer containing sodium nitrite is 20 μm or more and 100 μm or less regardless of a single layer or a multilayer. Preferably, they are 30 micrometers or more and 90 micrometers or less, More preferably, they are 40 micrometers or more and 80 micrometers or less. When the thickness is less than 20 μm, the rust prevention performance is not sufficient. On the other hand, when the thickness is 100 μm or more, the rust prevention performance is not improved and the transparency is lowered and the visibility is deteriorated.

  Furthermore, the content concentration of sodium nitrite is more than 0.3% by weight and less than 5% by weight with respect to the total weight of the film. Preferably, they are 0.35 weight% or more and 4 weight% or less, More preferably, they are 0.4 weight% or more and 3 weight% or less. When the content is 0.3% by weight or less, the rust prevention performance deteriorates. On the other hand, when the content is 5% by weight or more, the rust prevention performance is not improved, and the rust preventive powder may float or fall off.

  The film containing sodium nitrite as a rust inhibitor formed by the above method prints GHS label information recommended by the United Nations. Examples of printing methods include letterpress printing such as resin letterpress printing and flexographic printing, intaglio printing such as gravure printing, planographic printing such as offset printing, and silk screen printing. Further, a plateless method in which printing is directly performed on a film by ink jet or thermal transfer can be used. As the printing ink color, red and black two-color printing in which the characters are black and the hazard pictogram frame is red is preferable, and language display corresponding to the exporting country is desired. However, the present invention is not limited to this.

  Films made of polyolefin resin generally have a low surface energy and are inactive, so the adhesion of printing ink is often insufficient. Before printing with printing ink, by corona treatment, flame treatment or gas plasma treatment, It is desirable to improve hydrophilicity by introducing a polar functional group into the film surface. Specifically, the adhesion of the printing ink is improved by setting the wetting tension to 40 mN / m or more by surface treatment. Preferably, it is 45 mN / m, more preferably 50 mN / m or more. When the wetting tension is less than 40 mN / m, there may be a problem that the printing ink is peeled off due to rubbing of the film surface or the like.

  The formed rust preventive film can be processed into various bags according to use. For example, a two-sided bag, a three-sided bag, a three-sided bag with a chuck, a jointed bag, a gusset bag, a bottom gusset bag, a stand bag, a stand chuck bag, and the like can be given.

  In a rust-proof film bag formed by heat sealing and cutting from a sheet of rust-proof film formed by the inflation method, a so-called pitch printing method in which the seal cut pitch is a multiple of the pitch (period) of the print design Thus, it is possible to produce a rust-proof film bag displaying hazard information based on at least one GHS per bag. By printing the label information without missing each bag, information such as hazards can be transmitted to the end user without fail, which is excellent from the viewpoint of legal compliance and compliance.

  Since endless printing where the seal cut pitch and the pitch (cycle) of the print design are not linked, printing is done randomly, so when separating the bag from the film sheet by seal cut, the entire print design It may be interrupted without being displayed. Further, there is a problem that the printing ink is melted by heat sealing, and the heat sealing portion is stained.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the following, Examples 1, 2, and 5 are read as Reference Examples 1, 2, and 5, respectively.

<Preparation of rust preventive master batch>
Master batch A: 10 parts by weight of sodium nitrite and polyethylene resin (made by Nippon Polyethylene, trade name “Novatech LD LF125E” MFR: 0.4 g / min, density: 0.922 g / cm ³ , melting point: 111 ° C., described below 90% by weight was kneaded with a biaxial kneader to produce a rust preventive master batch A.
Master batch B: 10 parts by weight of ammonium benzoate and 90 parts by weight of polyethylene resin were kneaded with a biaxial kneader to prepare a rust preventive master batch B.

<Film formation>
The masterbatch and the polyethylene resin were dry blended at the ratios shown in Table 1, and a rust preventive film was formed with an inflation extrusion film forming machine. In the formation of the multilayer film, a multilayer die capable of three types and three layers was used. Moreover, the corona treatment was performed on the surface of one side of the anticorrosion film online before winding after film formation.

<Printing and bag making>
Black ink (Osaka Printing Ink Manufacturing, trade name: POC-II670 black) and red ink (Osaka Printing Ink Manufacturing, trade name: POC-II535) are printed on the corona-treated surface of the anticorrosive film by a gravure printing machine. After printing the GHS label information according to the UN recommendation by two-color printing using gold red), bag making processing was performed to produce a rust-proof film bag.
The conditions and methods for film formation and printing in Examples and Comparative Examples are shown in Table 1.

  Pitch printing is a printing method in which a printing design is printed for each bag of anticorrosive film, and the printing design does not become unreadable when the bag is separated from the film sheet by a seal cut. Endless printing is a printing method in which printing is randomly performed, and when the bag is cut off from the film sheet by a seal cut, the entire print design is not printed and may be interrupted.

The antirust films and antirust film bags produced in the examples and comparative examples were evaluated by the following methods, and the results are shown in Table 2.
<Rust prevention performance evaluation>
The SPCC steel plate was polished with # 240 abrasive paper, degreased with kerosene, methanol, and acetone, then a test piece was placed in each anticorrosive film bag, hermetically sealed with heat seal, and the environmental test of the following cycle was performed 30 times. . 1 cycle: 5 ° C., 3 hr → 50 ° C., 95% RH, 3 hr → 5 ° C., 3 hr → 50 ° C., 95% RH, 15 hr. Corrosion and no discoloration were evaluated as ◎, slight corrosion and discoloration area less than 10% as ○, mild corrosion and discoloration area as less than 10 to 30% as Δ, clear corrosion and discoloration area as less than 30 to 50% as x. .

<Evaluation of printing ink adhesion>
For the printing ink adhesion, use a cutter knife to cut a grid-like cut at 1 mm intervals on the printed part, peel off after applying cellophane tape (manufactured by Nichiban Co., Ltd.), and no peeling part. The case where the peeled portion was present was evaluated as x.

<Evaluation of print visibility>
UN-recommended GHS label printing has good visibility and the entire label is printed on a single bag with ○, and fine characters can be printed with high reproducibility and clear. did. On the other hand, the case where the visibility of the label printing portion was poor due to the printing ink adhering stain at the heat seal portion, or the case where a part of the label printing portion was not displayed due to chipping of the printing portion or the like was rated as x.

  The rust prevention film and the rust prevention film bag according to the present invention have a high rust prevention effect, the contents can be visually recognized from the outside, and label information such as hazards based on the UN Recommendation GHS is printed clearly and robustly. Therefore, it is extremely useful in practice.

Claims (3)

A rust preventive film containing a polyolefin resin and a rust preventive agent,
The rust-proof film has a multilayer structure including at least an innermost layer, an intermediate layer, and an outermost layer,
The innermost layer is a layer arranged on the side of the film that wraps and contacts the metal, and contains sodium nitrite as a rust inhibitor,
The outermost layer does not contain a rust inhibitor,
The intermediate layer includes at least one selected from nitrites, amine compounds, urea compounds, benzotriazole compounds, fatty acid compounds and salts thereof, and aromatic fatty acid compounds and salts thereof,
The content of sodium nitrite for the anticorrosive film total amount, rather less than the number 5 wt% than 0.3 wt%,
The wetting tension of the printed surface of the outermost layer is 40 mN / m or more,
Label information is displayed by printing on the printed surface . The innermost layer of the thickness is 20μm or more 100μm or less, antirust film according to claim 1. A rust-proof film bag made from the rust-proof film according to claim 1 by heat sealing and cutting, wherein the seal cut pitch is a multiple of the pitch (cycle) of the print design, and is the lowest in one bag. anticorrosive film bag, characterized in that one of the label information is displayed in the print.

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