JP4888680B2 - Antistatic agent and method of using the same - Google Patents

Description

  The present invention relates to an antistatic agent for plastics and chemical fibers and an antistatic method using the same. More specifically, the present invention relates to an antistatic agent comprising a polymerizable ionic liquid monomer or polymer and a method of using the same.

  In general, chemical fibers and plastics are electrically insulating, and the accumulation of charge on them due to friction can cause troublesome problems during use and during the manufacturing process, and can sometimes trigger fires and explosions.

  The amount of charge on an object is a balance between the generation speed and the disappearance speed. Therefore, in order to reduce the charge amount, the generation speed may be reduced or the disappearance speed may be increased. However, since the friction that causes the generation of static electricity is inevitably accompanied during manufacture or use, there is a limit to reducing this. Therefore, practical measures are based on increasing the charge dispersion or leakage rate.

  One method for increasing the rate of static electricity disappearance is to use an antistatic agent. The antistatic agent is based on the principle of increasing the rate of static electricity disappearance by increasing the ion or electrical conductivity.

  Organic compounds generally known to be effective for antistatic are long chain aliphatic amines and amides, quaternary ammonium salts, esters of fatty acids and their derivatives, sulfonates such as alkylated aromatic sulfonic acids, polyethers It belongs to polyols and derivatives thereof, polyhydric alcohols and derivatives thereof, phosphoric acid derivatives and the like. These common disadvantages include poor durability, including wash resistance, due to poor compatibility or affinity with the polymer of the material, bleed to the surface when kneaded into the raw material, physical properties of the molded product, such as hue. In other words, it adversely affects transparency, mechanical strength, heat resistance and the like, requires a relatively large amount of addition to exert its effect, and decomposes at the melting temperature of the raw material polymer. Accordingly, there remains a need for antistatic agents for plastics that have improved these drawbacks.

  The present invention provides chemical fibers and plastic antistatic agents based on polymerizable quaternary ammonium room temperature molten salt monomers. Quaternary ammonium room temperature molten salt is known as an ionic liquid, and has a remarkably high ion density as compared with a solution, and naturally has high ion and electrical conductivity. For this reason, it has attracted attention as an electrolyte medium for lithium ion batteries, for example. However, as the name suggests, ionic liquids are liquids at room temperature, so they have poor compatibility and affinity with polymers, and have the same disadvantages as other quaternary ammonium salts.

  Solid quaternary ammonium salt polymers having electrochemical properties similar to ionic liquids are also known. This can be obtained by polymerizing a monomer having a polymerizable functional group introduced into an ammonium cation of an ionic liquid, alone or with another monomer. Hereinafter, this polymer is referred to as “ionic liquid polymer”. Pre-polymerized ionic liquid polymers are also included in the present invention. If it is difficult to apply in the form of a polymer, a composition containing an ionic liquid monomer before polymerization and a polymerization initiator is applied to the raw material polymer and polymerized in situ to form an ionic liquid polymer.

  Here, “polymerizable ionic liquid monomer” means an ammonium cation (including pyridinium and imidazolium) having a polymerizable functional group (for example, vinyl group, allyl group and (meth) acryloyl group), an anion containing fluorine, Means salt.

The “anion containing fluorine” means an anion derived from an atomic group having a covalently bonded fluorine, and does not include the fluorine ion F ⁻ .

  “Molded product” includes an object formed by extrusion molding, injection molding, casting, compression molding, or the like, as well as a fabric of synthetic or semi-synthetic fiber.

  The quaternary ammonium salt monomer is a salt of an ammonium cation having an ethylenically unsaturated group (including vinyl and allyl groups) and a fluorine atom-containing anion.

  Typical examples of ammonium cation species are 1-vinyl-3-alkylimidazolium cation, 4-vinyl-1-alkylpyridinium cation, 1-alkyl-3-allylimidazolium cation, 1- (4-vinylbenzyl) -3. -Alkyl imidazolium cation, 1- (2-vinyloxyethyl) -3-alkyl imidazolium cation, 1-vinyl imidazolium cation, 1-allyl imidazolium cation, N-allyl benzimidazolium cation, N, N-diallyl Including alkyl ammonium cation, N-alkyl piperidinium cation, vinyl benzyl trialkyl ammonium cation, and N- (meth) acryloyloxyalkyl-N, N, N-trialkyl ammonium cation.

  Typical examples of fluorine-containing anion species are bis [(trifluoromethyl) sulfonyl] amide anion, 2,2,2-trifluoro-N- (trifluoromethylsulfonyl) acetamide anion, bis [(pentafluoroethyl) sulfonyl]. Including amide anion, bis (fluorosulfonyl) amide anion, tetrafluoroborate anion, and trifluoromethanesulfonate anion.

  Ionic liquid monomers can be used for the antistatic of chemical fibers and plastics in the form of monomers or in the form of their polymers.

  When used in the form of a monomer, a composition containing a required amount of a polymerization initiator is added to a plastic material before molding, such as pellets, molding compound, etc., and extrusion, molding, injection molding, compression molding, calendering, etc. The ionic liquid polymer can be polymerized in situ by heat during molding. In this case, the polymerization initiator is a peroxide-based or azo-based thermal polymerization initiator.

  A composition comprising an ionic liquid monomer and a polymerization initiator is particularly useful for forming a transparent thin antistatic hardcoat on a transparent hard plastic molding such as acrylic resin, polycarbonate, polystyrene. In this case, if necessary, the composition is diluted with a suitable organic solvent and then applied to the surface of the molding by spraying, dipping or other methods, and the ionic liquid monomer is polymerized on the surface of the plastic molding by the heat of drying. A thin antistatic layer can be formed integrally with the molded product. Since the polymerization is performed in contact with the plastic molded product, it is considered that crosslinking occurs between the raw plastic and the ionic liquid polymer, and the formed antistatic film does not easily fall off. If heating of the base plastic molding is not preferred, the composition containing the photopolymerization initiator can be polymerized by irradiation with light such as ultraviolet rays.

  A composition comprising an ionic liquid monomer and a polymerization initiator can be used to form an antistatic layer of an ionic liquid polymer, generally by post-processing into a plastic molding by the above method. For example, if the temperature for melting or curing the plastic is close to or higher than the decomposition temperature of the ionic liquid monomer or polymer, it is not suitable for addition to the plastic material before molding, but according to the above method to the plastic product after molding It is preferable to form an antistatic film of an ionic liquid polymer by post-processing.

  From the above description, it is possible to polymerize the ionic liquid monomer in advance and add the resulting polymer to the plastic material before molding, or coat the plastic product after molding with a solution of the ionic liquid polymer. It can be easily understood that the antistatic of the plastic product can be performed.

  Examples of thermoplastics that are subject to antistatic according to the present invention are polyolefins such as polyethylene and polypropylene; polystyrene; polyvinyl chloride; polyacrylates such as polymethyl methacrylate; polyethylene terephthalate; polybutylene terephthalate and polyoxybenzoate. Polyesters such as polyesters; aliphatic and aromatic polyamides; polysulfones; polyether sulfones; polycarbonates; polyether ether ketones; polyimides; fluororesins such as PTFE; polyurethanes; and polymer blends and polymer alloys thereof. . Examples of thermosetting plastics include but are not limited to phenolic resins, epoxy resins and unsaturated polyester resins.

  The antistatic of the plastic products mentioned above can be applied to chemical fibers. In this case, the ionic liquid monomer and the polymerization initiator or the ionic liquid polymer can be added to the raw polymer melt or solvent solution, and melt spinning or dry spinning can be performed. A nonwoven fabric can also be manufactured by the spunbond method from the raw material which added the antistatic composition of this invention. Antistatic by post-processing of primary and secondary products such as filaments, staples, processed yarns, fabrics, etc. is also possible by the same method as above.

  Examples of target chemical fibers include polyester fibers, polyamide fibers, acrylic fibers, polyvinyl chloride fibers, polyolefin fibers, polyurethane fibers, fluorine fibers, acetate fibers, and the like.

In general, the amount of the antistatic agent added to the inside of the plastic depends on the antistatic ability, the relative humidity, the temperature, etc. of the specific antistatic agent, but is generally about 0.1%. In the case of the present invention, this is an amount that reduces the surface resistivity of the antistatic plastic to the order of less than 10 ¹⁰ . In the case of the present invention, the target surface resistivity can be sufficiently lowered with an internal addition amount of 0.1%. Of course, more than 0.1% may be added. When forming a thin antistatic layer on the surface of a plastic molded article, the surface resistivity depends on the resistance value of the ionic liquid polymer itself, so that the formed ionic liquid polymer is sufficient to form a continuous film. The coating amount is sufficient.

Synthesis of N-methacryloyloxyethyl-N, N, N-trimethylammonium bis [(trifluoromethyl) sulfonyl] amide (MOETMA-TFSI):
N-methacryloyloxyethyl-N, N, N-trimethylammonium chloride (103.9 g, 0.5 mol) was melted in 100 g of water and stirred at room temperature with bis [(trifluoromethyl) sulfonyl] imidic acid (HTFSI). 200.7 g (0.5 mol) of a 70% aqueous solution was added dropwise, and stirring was continued for 1 hour at room temperature after completion of the dropwise addition. The produced oil layer was separated, washed several times with 50 ml of water, and vacuum-dried at 40 ° C. for 2 hours to obtain 208 g (92.5%) of MOETMA-TFSI as a colorless transparent liquid. The structure of the product was confirmed by FT-IR and ¹ H-NMR. MOETMA-TFSI was subjected to thermogravimetric analysis in the air at a heating rate of 10 ° C./min. As a result, the thermal decomposition temperature was 354.6 ° C.

To a 10% solution of MOETMA-TFSI synthesized in Example 1 in ethanol, azobisisobutyronitrile as a polymerization initiator was added at a weight ratio of 0.5% with respect to MOETMA-TFSI. This liquid was spray-coated on the surface of a transparent acrylic resin plate having a thickness of 3 mm as a solid content so that the coating amount was 0.6 mg / cm ² and dried at 90 ° C. under reduced pressure. A colorless and transparent thin film was formed on the surface that was indistinguishable from the plate before application with the naked eye. The surface resistivity (JIS K 6900) of the coated plate was measured at 25 ° C. and different relative humidity, and the following results were obtained.

Plate after plate application before RH application 10% 9.9 × 10 ¹¹ Ω or more 2.3 × 10 ⁹ Ω
20% 9.9 × 10 ¹¹ Ω or more 5.3 × 10 ⁹ Ω
30% 9.9 × 10 ¹¹ Ω or more 5.2 × 10 ⁹ Ω
40% 9.9 × 10 ¹¹ Ω or more 4.3 × 10 ⁹ Ω
50% 9.9 × 10 ¹¹ Ω or more 5.5 × 10 ⁹ Ω
60% 9.9 × 10 ¹¹ Ω or more 3.2 × 10 ⁹ Ω
This is a result of measurement using a Megaresta (manufactured by Cicid Electrostatics) SSD-R probe as a surface resistance measuring device at an applied voltage of 100 V × 10 sec.

Azobisisobutyronitrile as a polymerization initiator was added to MOETMA-TFSI synthesized in Example 1 at a weight ratio of 0.5% with respect to MOTEMA-TFSI. When this was heated at 90 ° C., a colorless and transparent solid was obtained. This solid is dissolved in acetone to a weight ratio of 5%, spray-coated on the surface of a PET film or transparent acrylic resin plate to a solid content of 0.6 mg / cm ² and dried at 90 ° C. It was. A colorless and transparent film was formed on the surface that was indistinguishable from the plate before application with the naked eye. The surface resistivity of the coated plate was measured at 25 ° C. and different relative humidity according to JIS K 6900, and the following results were obtained.
Plate 10% after plate application before RH application 9.9 × 10 ¹¹ Ω or more 4.3 × 10 ⁹ Ω
20% 9.9 × 10 ¹¹ Ω or more 3.1 × 10 ⁹ Ω
30% 9.9 × 10 ¹¹ Ω or more 2.2 × 10 ⁹ Ω
40% 9.9 × 10 ¹¹ Ω or more 4.3 × 10 ⁹ Ω
50% 9.9 × 10 ¹¹ Ω or more 5.3 × 10 ⁹ Ω
60% 9.9 × 10 ¹¹ Ω or more 3.1 × 10 ⁹ Ω
This is a result of measurement using a Megaresta (manufactured by Cicid Electrostatics) SSD-R probe as a surface resistance measuring device at an applied voltage of 100 V × 10 sec.

Synthesis of N- (4-vinylbenzyl) -N, N, N-trimethylammonium bis [(trifluoromethyl) sulfonyl] amide (VBTMA-TFSI):
100 g (0.53 mol) of N- (4-vinylbenzyl) -N, N, N-trimethylammonium chloride was dissolved in 100 g of water, and 70% of bis [(trifluoromethyl) sulfonyl] imidic acid (HTFSI) was dissolved therein. 203.2 g (0.503 mol) of an aqueous solution was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was stirred at 45 ° C. for 1 hour, the produced oil phase was separated, washed with 50 ml of water, and washing was repeated until the washing became neutral. The washed oil layer was dried at 40 ° C. for 2 hours to obtain 200 g (90.1%) of VBTMA-TFSI as a colorless transparent liquid. The structure was confirmed by FT-IR and ¹ H-NMR.

To a 10% dimethylacetamide solution of VBTMA-TFSI synthesized in Example 3, 0.5% by weight of azobisisobutyronitrile was added to VBTMA-TFST, and this solution was added to a 3 mm thick polystyrene plate. The surface was spray coated so that the coating amount was 0.6 mg / cm ² as a solid content, and dried at 90 ° C. under reduced pressure. A colorless and transparent thin film was formed on the surface of the plate, which was indistinguishable from the plate before application with the naked eye. The surface resistivity of the coated panel was measured at 25 ° C. and different relative humidity, and the following results were obtained.

Plate after plate application before RH application 10% 9.9 × 10 ¹¹ Ω or more 8.5 × 10 ⁸ Ω
20% 9.9 × 10 ¹¹ Ω or more 7.7 × 10 ⁸ Ω
30% 9.9 × 10 ¹¹ Ω or more 6.6 × 10 ⁸ Ω
40% 9.9 × 10 ¹¹ Ω or more 7.8 × 10 ⁸ Ω
50% 9.9 × 10 ¹¹ Ω or higher 7.0 × 10 ⁸ Ω
60% 9.9 × 10 ¹¹ Ω or more 8.5 × 10 ⁸ Ω

A radical polymerization initiator having a weight ratio of 0.5% was added to MOTEMA-TFSI synthesized in Example 1, and the mixture was heated at 90 ° C. for 5 hours. This gave a colorless solid.
The obtained bulk polymer was added by 3% by weight to a polyethylene terephthalate chip, melted at 280 ° C., and extruded from a syringe to obtain a filament. Separately, this melt was cast on a glass plate to form a film, and the surface resistivity was measured to find 5.8 × 10 ⁹ Ω.

A radical polymerization initiator having a weight ratio of 0.5% was added to MOTEMA-TFSI synthesized in Example 1, and the mixture was heated at 90 ° C. for 5 hours. This gave a colorless solid.
The obtained bulk polymer was added to a polyacrylonitrile dimethylformamide solution at a ratio of 3% by weight with respect to polyacrylonitrile, and the solution was discharged from a syringe and dried to obtain a filament. Separately, the spinning solution was cast on a glass plate and the solvent was removed, and a film was prepared. The surface resistivity was measured and found to be 7.3 × 10 ⁸ Ω. The film was immersed in water at room temperature for 1 week, pulled up, dried completely, and measured for surface resistivity again.

Claims (2)

(A) an ionic liquid monomer comprising a salt of a quaternary ammonium cation having a polymerizable functional group introduced therein and a fluorine-containing anion; and (b) an ionicity having a polymerization initiator and having the polymerizable functional group introduced thereinto. Liquid monomers include 1-vinyl-3-alkylimidazolium cation, 4-vinyl-1-alkylpyridinium cation, 1- (4-vinylbenzyl) -3-alkylimidazolium cation, 1- (2-vinyloxyethyl) A cation selected from the group consisting of a -3-alkylimidazolium cation, a 1-vinylimidazolium cation, a vinylbenzyltrialkylammonium cation, and an N- (meth) acryloyloxyalkyl-N, N, N-trialkylammonium cation Bis [(trifluoromethyl) sulfonyl Amide anion, 2,2,2-trifluoro-N- (trifluoromethylsulfonyl) acetamide anion, bis [(pentafluoroethyl) sulfonyl] amide anion, bis (fluorosulfonyl) amide anion, tetrafluoroborate anion, and An antistatic composition which is a salt with an anion selected from the group consisting of trifluoromethanesulfonate anions. The composition according to claim 1 is added to a plastic material or coated on the surface of a plastic molded article, and then the ionic liquid monomer having a polymerizable group and the plastic are subjected to a crosslinking reaction by thermal polymerization or photopolymerization. An antistatic method for a plastic molded article comprising a step of causing