JP2006137149A - Antistatic film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antistatic sealant film, an antistatic film and an antistatic bag each showing excellence in anti-blocking , slipperiness and adhesion. <P>SOLUTION: The antistatic sealant film comprises at least two layers of a layer (A) of a polyolefin-based resin and a layer (B) containing a polyolefin-based resin, an antistatic agent composed of a 12C to 18C alkylsulfonate and an ester compound of a polyhydric alcohol and a 12C to 18C aliphatic carboxylic acid and an anti-blocking agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyolefin film for lamination mainly used for commercial packaging. More specifically, the present invention relates to a polyolefin resin film excellent in conventional environmental sanitation.

For packaging foods, pharmaceuticals, industrial products, etc., a laminate film in which a polyolefin-based sealant film is bonded to a base film such as polyethylene, polyester, polyamide, etc. by a method such as a sand laminate method or a dry laminate method is widely used. . Among them, the laminate film subjected to the antistatic treatment is widely used for packing rice husks, various powders, electronic component materials and the like.
As the antistatic film, a film obtained by kneading a surfactant as an antistatic agent in a polyolefin resin is widely used. These antistatic films are antistatic by allowing the antistatic agent contained in the film to bleed on the film surface and forming a moisture film on the film surface by the hydrophilic functional groups in the bleed antistatic agent to release the charged static electricity. Demonstrate the effect.

  On the other hand, various additives are added to the polyolefin-based film in order to reduce problems that occur during the production, post-processing and use of the film. For example, an anti-blocking agent or a slip agent is kneaded in order to improve slippage between the films in order to prevent the films from blocking each other when the films are wound or stacked on a roll. These anti-blocking agents, slip agents, and the like are usually low molecular weight materials and are likely to bleed on the surface in order to easily exert their effects.

  That is, the antistatic film made of the polyolefin-based resin has various problems because it contains an antistatic agent, an antiblocking agent, a slip agent and the like as described above. For example, since the anti-blocking agent or slip agent bleeds on the surface, the antistatic effect decreases, and when the antistatic film is processed into a bag shape, There was a problem that the adhesive strength of the adhesive surface for processing into a bag shape for blocking agent, slip agent and the like was lowered, and further the contents were contaminated.

  The present invention solves the above problems and provides an antistatic sealant film, an antistatic film and an antistatic bag excellent in blocking resistance, slipperiness and adhesiveness.

  The invention according to claim 1 includes a layer (A) comprising a polyolefin resin, a polyolefin resin, an alkyl sulfonate having 12 to 18 carbon atoms, a polyhydric alcohol and an aliphatic carboxylic acid having 12 to 18 carbon atoms. An antistatic sealant film comprising at least two layers of an antistatic agent comprising an ester compound comprising the above and a layer (B) comprising an antiblocking agent.

  The invention according to claim 2 is the antistatic sealant film according to claim 1, wherein the amount of the high molecular weight antistatic agent in the layer (B) is 3 to 10% by weight.

  According to a third aspect of the present invention, the antiblocking agent is surface-treated inorganic particles having a particle shape of 3 μm to 10 μm and / or organic particles or glass particles having a particle diameter of 3 μm to 10 μm. This is a sealant film.

  Invention of Claim 4 is an antistatic packaging film formed by laminating | stacking the layer (A) side of the sealant film of any one of Claims 1-3 on a base film.

  A fifth aspect of the present invention is an antistatic bag comprising the antistatic packaging film according to the fourth aspect.

  The polyolefin resin used for the layer (A) and the layer (B) of the present invention may be the same material or different. It does not specifically limit as said polyolefin resin, A polyethylene resin and a polypropylene resin are mentioned. Examples of the polyethylene resin include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene, high density polyethylene, a copolymer of ethylene and α-olefin, an ethylene-vinyl acetate copolymer, and the like. Examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and the like. These polyethylene resins may be used alone or in combination of two or more. Examples of the polypropylene resin include polypropylene homopolymers, copolymers of propylene and α-olefins, and the α-olefins are generally ethylene, 1-butene, 1-pentene, 1-hexene, Examples include 1-octene and 4-methyl-1-pentene. These polypropylene resins may be used alone or in combination of two or more.

Of the above resins, preferred resins for the layer (A) are LDPE and LLDPE, and particularly preferred is LLDPE. More preferably, it is LLDPE having an MFR of 1.0 to 3.0 g / 10 min (190 ° C.) and a density of 0.910 to 0.930. For the layer (B), LDPE and LLDPE are preferred, and LLDPE is particularly preferred from the viewpoints of flexibility, adhesiveness during bag making processing, and the like. More preferably, it is made of a copolymer of ethylene and an α-olefin having 4 to 8 carbon atoms, and has an MFR of 1.5 to 3.5 g / 10 minutes (190 ° C.) and a density of 0.915 to 0.935. LLDPE.
The most preferable combination of the layer (A) and the layer (B) is that the resin for the layer (A) has an MFR of 1.0 to 2.0 g / 10 min (190 ° C.) and density from the viewpoint of moldability, ease of handling of the film, and the like. The resin for the layer (B) is an LLDPE having an MFR of 2.0 to 3.0 g / 10 min (190 ° C.) and a density of 0.920 to 0.930.

The antistatic agent used in the present invention contains an alkyl sulfonate having an alkyl group having 12 to 18 carbon atoms, an ester compound composed of a polyhydric alcohol and an aliphatic carboxylic acid having 12 to 18 carbon atoms. An antistatic agent.
The alkyl sulfonate having 12 to 18 carbon atoms in the alkyl group is not particularly limited, and examples thereof include lithium, sodium, and potassium salts such as dodecyl sulfone sun, tetradecyl sulfonic acid, pentadecyl sulfonic acid, and octadecyl sulfonic acid. Etc. Although the said alkyl sulfonate may be used independently, it is preferable that 2 or more types are mixed and used.

Examples of the ester of the polyhydric alcohol and the aliphatic carboxylic acid having 12 to 18 carbon atoms include tetravalent or pentavalent polyols such as diglycerin, sorbitan and triglycerin, lauric acid, myristic acid, palmitic acid, stearin. And esters with aliphatic carboxylic acids such as acids, oleic acid, and linoleic acid.
Although the ratio of the said alkyl sulfonate and ester is not specifically limited, 60 / 40-80 / 20 (weight ratio) is preferable.

  The amount of the antistatic agent is preferably 3 to 10% by weight in the layer (B). If it is less than 3% by weight, the antistatic effect is not sufficient, and if it exceeds 10% by weight, the adhesion of the layer (B) may be inhibited, which is not preferable.

  The antiblocking agent used in the present invention is not particularly limited as long as it is solid at room temperature and hardly bleeds even when added to and kneaded with polyolefin, and may be inorganic or organic. Examples of inorganic substances include silica, zeolite, calcium carbonate, and the like. These inorganic materials are preferably surface-treated with a silane coupling agent, a titanate coupling agent, a carboxylic acid such as stearic acid or the like in order to facilitate dispersion in the polyolefin resin. The inorganic material preferably has a particle diameter of 3 μm to 10 μm. As the organic substance, acrylic resin particles, fluorine resin particles, and the like having a particle diameter of 5 μm to 15 μm are preferably used. By using particles having a particle size in the above range, uniform kneading and dispersion into the resin are possible, and a film having excellent transparency, appearance, and blocking resistance can be obtained. Glass particles having a particle diameter of 5 μm to 15 μm may be used instead of the organic particles.

  The anti-blocking agent may be used alone or in combination of two or more, and in particular, inorganic substances such as silica and zeolite having a particle diameter of 3 μm to 10 μm and an acrylic resin having a particle diameter of 5 μm to 15 μm. It is preferable to use particles, fluorine resin particles, glass particles and the like in combination. In the case of only inorganic substances such as silica and zeolite having a particle diameter of 3 μm to 10 μm, the transparency is likely to be hindered. Tends to decrease.

  The addition amount of the antiblocking agent is preferably 3 to 20% by weight in the layer (B). When the amount of the anti-blocking agent is less than 3% by weight, the effect of the anti-blocking agent is hardly recognized, and when it exceeds 20% by weight, the transparency may be impaired. Further, as described above, it is preferable that inorganic substances such as silica and zeolite having a particle diameter of 3 μm to 10 μm and acrylic resin particles, fluorine resin particles, glass beads and the like having a particle diameter of 5 μm to 15 μm are used in combination. Are used, the amount of inorganic substances such as silica and zeolite having a particle diameter of 3 μm to 10 μm is preferably 2 to 10% by weight in the layer (B), and acrylic resin particles and fluorine resin particles of 5 μm to 15 μm. The amount of glass beads and the like is preferably 2 to 7% by weight in the layer (B).

  The sealant film of the present invention is a multilayer sealant film made of the above-described materials and containing at least a layer (A) in contact with the base film and a layer (B) in contact with the contents. The thickness of each layer in the sealant film is not particularly limited and may be appropriately determined depending on the use, the type of the base film, etc., but the thickness of the sealant film is usually 20 to 150 μm, and the thickness of the layer (B) is 5 to 75 μm.

  Although it does not specifically limit as a manufacturing method of the sealant film of this invention, For example, the method of extrusion-coating the material for layers (B) on the film which comprises a layer (A), The material for layers (A) The materials for the layer (B) are supplied to different extruders, and multilayer extrusion, multilayer inflation and the like can be mentioned. Of these, the multilayer inflation method is preferred because melt fracture is unlikely to occur, and stability of the antistatic effect and thermal deterioration are difficult to achieve.

  The antistatic sealant film of the present invention has the above-described configuration, and does not use generally used low molecular weight slip agents, surfactants, etc., and therefore has excellent slip properties and adhesive antistatic properties. It is a film. Further, an antistatic packaging film obtained by laminating the above-mentioned sealant film layer (A) on a base film is also a packaging film excellent in slipperiness and antistatic properties. Furthermore, since the packaging bag made of the antistatic packaging film in the previous period is a bag excellent in slipping property and antistatic property, it is suitably used for packaging rice husks, various powders, electronic component materials and the like.

Hereinafter, the present invention will be described with reference to examples (Example 1).
Resin for layer (A) consisting of linear low density polyethylene (2022L MFR: 2.1 density: 0.920 g / cm3, manufactured by Mitsui Petrochemical Co., Ltd.) and linear low density polyethylene (2525F MFR: 2.5 Density: 0.925 g / cm3, manufactured by Sumitomo Chemical Co., Ltd.) 100 parts by weight, anionic high molecular weight antistatic agent (SFM125, manufactured by Takemoto Yushi Co., Ltd.), 7 parts by weight, silica particles having an average particle size of 3 μm (particle size: 3 μm, large The resin composition for layer (B) comprising 3 parts by weight of Nissei Kasei Co., Ltd. and 5 parts by weight of acrylic fine particles (BB-32, particle size: 8 μm, manufactured by Idemitsu Chemical Co., Ltd.) And the resin composition for layer (B) were extruded by respective extruders and subjected to multilayer inflation molding to obtain a sealant film having a layer (A) of 30 μm and a layer (B) of 10 μm.
The obtained film layer (A) and polyester film (FE2021, manufactured by Phutamura Chemical Co., Ltd.) were dry laminated using an ester urethane adhesive (Takelac A-515) and an ether urethane adhesive (Takelac A-969V). Two types of laminated films for packaging were produced.

(Example 2)
In Example 1, two types of packaging laminate films were obtained in the same manner as in Example 1 except that silica particles were not used.

(Example 3)
In Example 1, two types of packaging laminate films were obtained in the same manner as in Example 1 except that the antistatic agent was 5 parts by weight.

(Comparative Example 1)
In Example 1, two types of packaging laminate films were obtained in the same manner as in Example 1 except that 3 parts by weight of a slip agent (erucamide) was added to the layer (B).

(Comparative Example 2)
In Example 1, two types of packaging laminate films were obtained in the same manner as in Example 1 except that no antistatic agent was used in the layer (B).

[Evaluation]
The following evaluation was performed on the packaging laminate film obtained above, and the results are shown in Table 1.
(Adhesive strength)
A 15 mm × 50 mm test piece was cut out from the film obtained above, and the substrate film and the sealant film were used in an environment of 23 ° C. and 65% RH using an autograph (AGS-J, manufactured by Shimadzu Corporation). The delamination strength of was measured.
(Surface resistivity)
A 100 mm × 100 mm test piece was cut out from the film obtained above and left for a predetermined time in an environment of 23 ° C. × 65% RH, and then ULTRA MEOHMMETER (detection device: SM-8210, measurement device: SM-8310). Was used to measure the surface resistance after 1 minute of charge.
(Charge half-life)
A 45 mm × 45 mm test piece was cut out from the film obtained above, and allowed to stand in an environment of 23 ° C. × 65% RH for a predetermined time in accordance with JIS L 1094. Then, the charge half-life was measured at an applied voltage of 8 kV.
(Coefficient of friction)
A test piece was prepared by adhering the layer (A) side of the film on a 200 mm × 100 mm frame, and affixing the layer (A) side of the film on an iron plate of 63 mm × 63 mm. Next, the test piece was placed on the pedestal so that the film layer (B) of the test piece was in contact with the film layer (B) on the pedestal, and then autographed at 23 ° C. and 65% RH. The test piece was pulled at a rate of 152 mm / min using (AGS-J, manufactured by Shimadzu Corporation). The maximum friction coefficient when the test piece started to move was determined as the static friction coefficient, and the average value of the friction coefficients during the movement was determined as the dynamic friction coefficient.

As is apparent from the table, Examples 1 to 3 according to the present invention have an excellent antistatic effect (low surface resistivity, short charge half-life) and excellent slipperiness (static, dynamic friction) Low coefficient). On the other hand, Comparative Examples 1 and 2 had poor antistatic properties.

Claims (5)

  A layer (A) composed of a polyolefin resin and a polyolefin resin, an alkyl sulfonate having 12 to 18 carbon atoms, an ester compound composed of a polyhydric alcohol and an aliphatic carboxylic acid having 12 to 18 carbon atoms. An antistatic sealant film comprising at least two layers (B) containing an antistatic agent and an antiblocking agent.   The antistatic sealant film according to claim 1, wherein the amount of the antistatic agent in the layer (B) is 5 to 15% by weight.   The antistatic agent according to claim 1 or 2, wherein the antiblocking agent is a surface-treated inorganic particle having a particle shape of 3 µm to 10 µm and / or an organic particle or a glass particle having a particle size of 3 µm to 10 µm. Sealant film.   The layer (A) side of the antistatic sealant film of any one of Claims 1-3 is laminated | stacked on a base film, The film for antistatic packaging characterized by the above-mentioned. An antistatic bag comprising the packaging film according to claim 4.