JP3061626U - Packaging materials for fluororesin particles - Google Patents

Abstract

(57) Abstract: Fluororesin particles filled in a packaging material can be prevented from being charged and adhere to the packaging material, a high raw material yield rate of the fluororesin particles can be obtained, and the fluorine to be packaged is obtained. Provided is a packaging material capable of preventing resin particles from being colored during molding. A packaging material is formed from a film having a polyester film as a base material and an outer surface provided with a layer containing a substance having an electrostatic induction preventing ability.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a packaging material having excellent antistatic ability for fluororesin particles.

[0002]

[Prior art]

 Fluororesin has the property of being most negatively charged in the charging train, and is easily charged with negative static electricity by various operations in the manufacturing process. In addition, it is charged by vibration and swing during transportation. The charged fluororesin particles not only have a bad effect on the filling of molding dies and hoppers of various molding machines, but also attract foreign substances such as dust and dirt in the working environment and cause foreign substances to enter. In addition, the charged fluororesin particles easily adhere to the packaging material and are not easily discharged, so that the raw material is wasted, particularly in the automatic charging method, and the raw material yield is reduced. Since fluoroplastics are usually much more expensive than other plastic materials, the yield of this raw material has a significant effect on the cost of the final molded product.

[0003] Usually, as a measure for preventing the resin from being charged, a conductive material such as carbon black is kneaded into the resin or a conductive coating agent is applied to the surface of a resin molded product. Fluororesins are often used for parts of semiconductor manufacturing equipment, and the use of additives such as conductive substances is not preferred in use. Also, regarding the kneading of surfactants and the application of a conductive coating agent, due to the high processing temperature of the fluororesin, the surfactant and the coating agent are thermally decomposed during the molding process, and the molded product may be colored. Becomes In addition, as for the spraying of ionized air or the like, even if the charge amount of the fluororesin particle itself is set to zero, it is recharged by shaking or vibration during transportation, so that only a temporary static elimination effect is obtained.

[0004]

[Problems to be solved by the invention]

 The present invention prevents the fluororesin particles filled in the packaging material from being charged and adheres to the packaging material, and is almost discharged from the packaging material to obtain a high raw material yield of the fluororesin particles. It is an object of the present invention to provide a packaging material which is made possible and capable of preventing coloring of the fluororesin particles to be packaged during molding.

[0005]

[Means for Solving the Problems]

 As a result of intensive studies, the inventors of the present invention used a polyester film as a base material, and constituted a packaging material with a film having a layer containing a substance having an anti-static induction ability on the outer surface of the base material. As a result, it has been found that the above problem is solved. That is, the present invention provides a packaging material for fluororesin particles, which is characterized by being formed from a film comprising a polyester film as a base material and a layer containing a substance having a function of preventing electrostatic induction on its outer surface. Is provided. Further, the present invention provides a packaging material for fluororesin particles in which the surface voltage of the laminated film after friction with polytetrafluoroethylene (hereinafter referred to as PTFE) is within ± 1 kV. is there. Another object of the present invention is to provide a packaging material for fluororesin particles in which the surface voltage of the laminated film after friction with PTFE is within ± 0.2 kV. Further, the present invention provides a packaging material for fluororesin particles, wherein the substance having an ability to prevent electrostatic induction is a crosslinkable copolymer having a carboxyl group and a quaternary ammonium base in a side chain. Things. The present invention also provides a packaging material for fluororesin particles, which is obtained by laminating a thermoplastic resin film on the surface of a layer containing a substance having a function of preventing electrostatic induction in the above packaging material. The present invention also provides a packaging material for fluororesin particles, wherein the polyester film is a biaxially stretched polyethylene terephthalate (hereinafter referred to as PET) film. The present invention also provides a packaging material for fluororesin particles, wherein the packaging material is a bag or a container.

[0006]

[Embodiment of the invention]

 What is packaged with the packaging material of the present invention is fluororesin particles. As the fluororesin, various fluororesins can be used. Specific examples thereof include PTFE, tetrafluoroethylene (hereinafter, referred to as TFE) -hexafluoropropylene copolymer (hereinafter, referred to as FEP), and TFE- Examples include perfluoro (alkyl vinyl ether) copolymer (hereinafter, referred to as PFA), TFE-ethylene copolymer (hereinafter, referred to as ETFE), polytrifluorochloroethylene, and polyvinylidene fluoride. Among them, PTFE, FEP, PFA, and ETFE are used as components of semiconductor manufacturing equipment, and it is necessary to prevent the addition of additives and impurities. These fluororesin particles are suitable for use in the packaging material of the present invention. In particular, PTFE is molded by compression molding or the like, unlike ordinary thermoplastic resins. Therefore, particles are often in the form of powder having a particle size of 1000 μm or less so that a dense preliminary molded product can be obtained. Strong and easy to take. Therefore, it is particularly suitable for using the packaging material of the present invention.

[0007] The shape of the fluororesin particles is not particularly limited, and examples thereof include shapes such as powder and pellets. The particle size of the fluororesin particles is not particularly limited, but may be usually from several μm to 10 mm. In addition, even if the packaged fluororesin particles are charged, when they are discharged from the packaging material of the present invention, they hardly remain in a packaging bag or the like, and do not affect the raw material yield. However, since the charged fluororesin particles can easily attract external dust when the packaging material is opened, it is desirable to reduce the charge amount of the fluororesin particles as much as possible. In particular, it is desirable to keep the surface voltage of the fluororesin particles within ± 1 kV.

[0008] The packaging material of the present invention is configured using a polyester film as a base material. Usually, various thermoplastic resin films are used for the thermoplastic resin film used for the packaging material. Various processing aids are added to these thermoplastic resins for the purpose of improving film forming processing performance. However, among these processing aids, organic ones may bleed out over time and adhere to the surface of the packaged contents. When the packaged object is a fluororesin particle, the fluororesin has a high molding temperature, and even if these additives are slightly attached, the fluororesin molded product may be colored. Generally, crystalline resins have better processing performance than non-crystalline resins, so that it is not necessary to add a large amount of processing aids such as plasticizers during film forming. However, among the crystalline resins, polyolefins such as polyethylene are liable to be oxidized and degraded during the molding process, and low molecular weight thermal decomposition products are generated. The low molecular weight thermal decomposition product migrates to the surface of the content of the fluororesin particles, and as a result, the fluororesin molded product may be colored.

By using the polyester film as a base material of the packaging material, it is possible to prevent coloring of a molded product obtained by using the packaged fluorine resin particles. Among the polyester films, biaxially stretched polyester films are preferable from the viewpoint of mechanical properties such as high elongation, and biaxially stretched PET is particularly preferable. The thickness of the polyester film, when the substrate is used alone, is usually preferably 500 μm or less, particularly preferably 200 μm or less. When used as a laminate film with a base material and one or more thermoplastic resin films, the thickness of the laminate film is usually preferably 500 μm or less, particularly preferably 200 μm or less. The thickness is usually 100 μm or less, particularly preferably 50 μm or less. The lower limit of the thickness of the polyester film is not particularly limited as long as it has a strength capable of wrapping the article to be packaged, but is preferably 5 μm or more.

[0010] The packaging material of the present invention is provided with a layer containing a substance having an ability to prevent electrostatic induction on the outer surface of the polyester film substrate. The ability to prevent static induction includes substances on the outer surface of the polyester film substrate when the surface of the polyester film is charged by contact / frictional electrification between the polyester film substrate and the fluororesin particles to be packaged. The ability to alleviate dielectric polarization generated in a layer. There is no particular limitation on the substance having such an electrostatic induction preventing property, but a substance that does not cause bleed-out at room temperature is desirable. Specific examples of the substance having the property of preventing static induction include an intramolecularly charged polymer having a cation group and an anion group in a side chain of the polymer, and more specifically, JP-A-07-252456 and JP-A-Hei. The crosslinkable copolymer having a carboxyl group and a quaternary ammonium base in the side chain described in 10-55894 is exemplified.

The cross-linkable copolymer having a carboxyl group and a quaternary ammonium group in the side chain includes a copolymer of a monomer having a carboxyl group at a terminal and a monomer having a quaternary ammonium group, Alternatively, a copolymer of the above monomer and a monomer having a polymerizable double bond may be used. Examples of the monomer having a terminal carboxyl group include acrylic acid, methacrylic acid, and acroyloxyethyl succinic acid. Examples of the monomer having a quaternary ammonium base include quaternary dimethylaminoethyl acrylate and quaternary dimethylaminoethyl methacrylate having a counter ion of chloride ion, sulfate ion, sulfonate ion or aliphatic sulfonate ion. Is mentioned. Examples of the monomer having a polymerizable double bond include alkyl acrylate, alkyl methacrylate, styrene, vinyl acetate, vinyl halide, and olefin.

[0012] The polymerization unit based on the monomer having a quaternary ammonium base is preferably in the range of 15 to 40 mol%, more preferably 15 to 40 mol%, based on the polymerization unit based on all the monomers of the crosslinkable copolymer. Configurations in the range of ~ 35 mol% are preferred. The polymerization unit based on a monomer having a carboxyl group at a terminal is preferably in a range of 3 to 13 mol%, more preferably 5 to 13 mol%, based on the polymerization unit based on all monomers of the crosslinkable copolymer. A composition in the range of 10 mol% is preferred. A quaternary ammonium base has the effect of imparting quick electrostatic polarization relaxation due to electrostatic polarization and ionic conductivity, and exhibits high heat resistance as a quaternary ammonium salt. The crosslinkable copolymer having a carboxyl group and a quaternary ammonium group in the side chain preferably undergoes a crosslinking reaction with a crosslinking curing agent to improve properties such as adhesion, durability, and heat resistance. Examples of the cross-linking curing agent include polyfunctional compounds, and specific examples thereof include epoxy derivatives such as diethylene glycol diglycidyl ether, glycerin diglycidyl ether, bisphenol A diglycidyl ether, and trimethylolpropane glycidyl ether. No. The addition amount of the crosslinking curing agent is preferably in the range of 15 to 30% by weight based on all the monomers of the crosslinking copolymer. The carboxyl group in the side chain contributes to the crosslinking reaction with the crosslinking curing agent.

Examples of the above-mentioned catalyst for ring-opening reaction curing of the epoxy derivative include imidazole derivatives such as 2-methylimidazole and 2-ethyl-4-methylimidazole, and polyamines and polyethyleneimine derivatives. The layer containing the substance having the ability to prevent electrostatic induction may contain, in addition to the substance having the ability to prevent electrostatic induction, a component for imparting or improving adhesiveness, other additives or a thermoplastic resin. Good. Examples of the thermoplastic resin include the same as those described in the thermoplastic resin film described later. The content of the substance having the ability to prevent electrostatic induction may be appropriately selected so that the packaging material of the present invention can have sufficient ability to prevent electrostatic induction, but is preferably in the range of 0.01 to 10 g / m ² . It is preferably in the range of 0.1 to 1 g / m ² .

The polyester film of the packaging material of the present invention has an antistatic property by having a layer containing a substance having an antistatic property. The surface charged voltage of the polyester film after friction with the PTFE is preferably ± 1 kV or less, particularly preferably ± 0.2 kV or less. The antistatic properties are as follows: the temperature is 25 ° C and the relative humidity is 60%, and the surface of the polyester film substrate on which the layer containing the substance having the antistatic property is not provided is contacted with a 25 mm square PTFE sheet. A load of about 1 kg was applied to the surface, and the film was rubbed back and forth 50 times, and the charged voltage on the film surface after the friction was measured and measured with an electrostatic potential measuring instrument.

In the packaging material of the present invention, the layer containing the substance having the ability to prevent electrostatic induction may be provided on the outer surface of the polyester film, but is not provided directly on the outer surface of the polyester film. Although it may be provided via a thermoplastic resin film, it is preferably provided directly on the outer surface of the polyester film. Further, in the packaging material of the present invention, it is preferable that the surface of the layer containing the substance having the ability to prevent electrostatic induction is laminated with a thermoplastic resin film. These thermoplastic resin films may be a single layer or two or more layers. By interposing a layer containing a substance having the ability to prevent electrostatic induction between the laminated films, workability and performance such as heat sealing are improved when the film is used to make a bag. There are no particular restrictions on the material of the thermoplastic resin film to be laminated, and low-density, linear low-density and high-density polyethylene films, stretched or unstretched polypropylene films, stretched or unstretched polyester films, polyvinyl chloride And a polyvinylidene chloride film. A polyethylene film is particularly preferred. When the number of the laminated films is three or more, it is not necessary to provide a layer containing a substance having a function of preventing electrostatic induction between all the resin films, and it is sufficient to provide the layer between at least one resin film. There is no particular limitation on the form of the substance having an antistatic property to be used, and it may be used alone or as a mixture with another thermoplastic resin in the form of liquid, powder, film or the like.

An adhesive layer or an anchor coat layer may be provided between the layer containing the substance having the ability to prevent electrostatic induction and the polyester film substrate. When it has a performance as an adhesive or an anchor coating agent, these may not be provided. When laminating resin films, they may be laminated with an adhesive layer or an anchor coating agent layer interposed. Examples of these adhesives and anchor coating agents include acrylic resin, polyvinyl ether resin, urethane resin, and silicone resin. Examples of the anchor coating agent include urethane-based and polyethyleneimine-based agents.

The shape of the packaging material of the present invention is not particularly limited as long as it can package the fluororesin particles, and examples thereof include bags and containers. Examples of the bag include a bag having a sectional view as shown in FIG. Bag making can be performed, for example, by laminating a cylindrical film at the bottom with the inner polyester film substrates. The bonding may be performed by heat sealing or an adhesive, but heat sealing is preferred. The packaging material of the present invention may be used alone, or may be used double or triple or more. Further, the packaging material of the present invention may be used as an interior material, and an exterior material may be covered on the outside. Examples of the exterior material include a paper bag, a paper drum, a flexible container, and the like. Also, in order to prevent foreign substances from being mixed in from these exterior materials, the interior materials may be double or more.The interior materials outside the double or more overlapping interior materials are not particularly limited, and the packaging material of the present invention is used. You may.

[0018]

【Example】

 Next, the present invention will be specifically described with reference to examples. However, the examples do not limit the present invention at all.

(Example 1) After drying an anchor coating agent (trade name: Bondip, manufactured by Altec Co., Ltd.) as a substance having an antistatic effect on a biaxially stretched PET film having a thickness of about 15 μm, 0.5 g / m ² and laminated on the coated surface with a polyethylene (hereinafter referred to as PE) film having a thickness of about 50 μm melted at about 300 ° C. to obtain a film having an effect of preventing static induction. This was made into a packaging bag (about 100 cm in length and about 100 cm in width) in which the inner surface was made of PET (hereinafter referred to as bag 1). In an environment of a temperature of 25 ° C. and a relative humidity of 60%, the PET film surface of the bag 1 was rubbed 50 times with a 25 mm square PTFE sheet so that the contact surface pressure was about 1 kg. The charged voltage on the PET surface after the friction was measured by a charged voltage measuring device (FM300, manufactured by SIMCO), and was 0 to 0.1 kV.

This bag 1 was packed with 10 kg of PTFE powder having an average particle diameter of about 400 μm, and then tied, and packaged using a paper drum having a diameter of about 55 cm and a height of about 33 cm as an exterior material. Next, using a lifter for mixing and discharging the drums, each of the packaged paper drums was vertically rotated for 30 minutes. By this operation, static electricity was generated in the PTFE powder in the filling bag, and the electrostatic potential on the surface of the PTFE powder was measured to be about -40 kV by using the charged voltage meter. After taking out the filling bag from the paper drum, holding the end by hand, and discharging the charged PTFE powder to another container, the PTFE powder hardly adhered to the bag 1 and the amount of adhesion was 43 g. .

Example 2 A bag 2 was prepared in the same manner as in Example 1 except that the following adhesive was used as an adhesive made of a substance having a function of preventing electrostatic induction. Preparation of an adhesive composed of a substance having an ability to prevent static induction: Methyl methacrylate, ethyl acrylate, acrylic acid and dimethyl sulfate quaternary chloride of dimethylaminoethyl methacrylate are mixed in a weight ratio of 45: 8: 4: 43. The copolymer was copolymerized in a mixed solution of isopropanol / water (mixing weight ratio 1/1) to obtain a transparent solution having a solid content of 30%. To this solution was added 20% by weight of diethylene glycol glycidyl ether as a crosslinking curing agent based on the solid content of the solution, and 2-methylimidazole was added as a catalyst in an amount of 5% by weight of diethylene glycol glycidyl ether to prepare a solution. A film was produced in the same manner as in Example 1, and was made into a bag (length: about 100 cm, width: about 100 cm, hereinafter referred to as bag 2). The charged voltage on the PET surface measured in the same manner as in Example 1 was 0 to 0.1 kV. In addition, when the adhesion of the PTFE powder to the bag 2 was observed in the same manner as in Example 1, there was almost no adhesion of the PTFE powder, and the amount of the adhesion was 41 g.

Comparative Example 1 A biaxially stretched PET film having a thickness of about 15 μm and a PE film having a thickness of about 50 μm were obtained by using a commercially available polyurethane-based anchor coat without using an adhesive having a function of preventing electrostatic induction. Using the agent, a laminate film was prepared and formed into a bag (length: about 100 cm, width: about 100 cm, hereinafter referred to as bag 3). The charged voltage on the PET surface measured in the same manner as in Example 1 was 3.6 to 4.9 kV. In the same manner as in Example 1, PTFE powder was filled and rotated vertically. By this operation, the electrostatic potential on the PTFE powder surface in the filling bag was about -40 kV, which was the same level as in Example 1. When the adhesion of the PTFE powder to the bag 3 was observed in the same manner as in Example 1, the adhesion of the PTFE powder was large and the amount of adhesion was 190 g.

[0023]

[Effect of the invention]

 The fluororesin particles packaged in the packaging material of the present invention have a small amount of adhesion to the packaging material at the time of discharge even in a sufficiently charged state, and a high yield of the fluororesin raw material can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a bag according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyester film base material 2 Layer containing substance which has electrostatic induction prevention ability

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08J 7/04 C08J 7/04 D C08L 33/02 C08L 33/02 (72) Inventor Shigeki Kobayashi 10 Goi Kaigan, Ichihara City, Chiba Prefecture Asahi Glass Fluoropolymers Co., Ltd.

Claims (7)

[Utility model registration claims] 1. A packaging material for fluororesin particles, comprising a polyester film as a base material and a film provided on its outer surface with a layer containing a substance having a function of preventing electrostatic induction. 2. The packaging material for fluororesin particles according to claim 1, wherein the surface voltage of the polyester film after friction with polytetrafluoroethylene is within ± 1 kV. 3. The packaging material for fluororesin particles according to claim 1, wherein the surface charged voltage of the polyester film surface after friction with polytetrafluoroethylene is within ± 0.2 kV. 4. The packaging for fluororesin particles according to claim 1, wherein the substance having an ability to prevent electrostatic induction is a crosslinkable copolymer having a carboxyl group and a quaternary ammonium base in a side chain. Wood. 5. A thermoplastic resin film is laminated on the surface of a layer containing a substance having a function of preventing electrostatic induction.
The packaging material for fluororesin particles according to any one of the above. 6. The packaging material for fluororesin particles according to claim 1, wherein the polyester film is a biaxially stretched polyethylene terephthalate film. 7. The packaging material is a bag or a container.
The packaging material for fluororesin particles according to any one of the above.