JP2006070062A - Antistatic hard coat coating, antistatic hard coat film using the same and molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an antistatic hard coat coating that has excellent leveling properties, provides a coating film having excellent transparency, scuff resistance and antistatic properties, an antistatic hard coat film having excellent transparency, scuff resistance and antistatic properties and a molding having a hard coat coating film having excellent transparency, scuff resistance and antistatic properties on the surface of a resin molding. <P>SOLUTION: The antistatic hard coat coating comprises an ionizing radiation-curable resin composition, a lithium salt compound and a polyether-modified compound. The antistatic hard coat film is formed by coating and curing the antistatic hard coat coating. The molding has the antistatic hard coat film on the surface of a resin molding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antistatic hard coat coating material having excellent scratch resistance and antistatic properties when formed into a coating film, and relates to an antistatic hard coat film and a molded body using the coating material. .

  In recent years, transparent materials for image display such as display screens, structural materials on walls and floors, window materials for machines installed in rooms, machines used in industrial dust-free rooms (clean rooms), etc. In addition to antistatic properties, the resin parts used in these electronic parts or their storage, transportation or manufacturing processes are required to have transparency, aesthetics or scratch resistance in order to maintain their performance.

  Conventionally, as a method for imparting antistatic properties to plastic products, surfactant type antistatic agents such as quaternary ammonium salts, conductive fine particles such as metal powders and carbon powders, and the like. The method of apply | coating to the inside or mixing in the inside has been taken.

  However, when a surfactant-type antistatic agent is used in the resin molded body as described above, it does not provide stable antistatic properties because it depends on the ambient humidity, and lacks durability and cures the resin. It tends to be a cause of inhibition of curing at the time, and has a problem of easily causing a decrease in scratch resistance.

  In addition, when using conductive fine particles, it is excellent in antistatic properties and sustainability without depending on humidity, but the resin molded body becomes opaque or colored, and it is difficult to see through the resin molded body. Has drawbacks. Further, since the content of the conductive fine particles in the antistatic hard coat film is high and hinders the curing of the resin, there is also a drawback that the scratch resistance is lowered. In addition, after such a resin molded body is subjected to heat molding such as bending, gaps are formed between the conductive fine particles, which causes a problem that the antistatic property is lowered. In addition, when the antistatic hard coat paint is used, the conductive fine particles easily settle and re-aggregate, so that there is a disadvantage that a coating having stable antistatic properties and scratch resistance cannot be obtained. .

  In order to solve such a problem, a technique of imparting antistatic properties by adding a lithium salt compound to a hard coat paint has been proposed (see Patent Document 1). However, when such a hard coat paint is applied only by adding a lithium salt compound, the leveling property is not so good, and there is a problem that unevenness tends to occur and a uniform and beautiful coating film cannot be obtained. . In addition, a coating film formed from such a paint does not always have sufficient antistatic properties.

JP 2003-41194 A (Claim 1)

  Accordingly, an object of the present invention is to provide an antistatic hard coat coating material having good leveling properties and having excellent transparency, scratch resistance, and antistatic properties when the coating film is formed. . Another object of the present invention is to provide an antistatic hard coat film having excellent transparency, scratch resistance, and antistatic properties. Another object of the present invention is to provide a molded article having a hard coat coating film excellent in transparency, scratch resistance, and antistatic properties on the surface of a resin molded article.

  In order to obtain a uniform and beautiful coating film, the present inventors have studied various leveling agents. By using a specific leveling agent, the antistatic property is dramatically improved and the scratch resistance is reduced. It has been found that a coating film without the above can be obtained.

  That is, the antistatic hard coat paint of the present invention is characterized by containing an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound.

  The antistatic hard coat film of the present invention is formed by applying and curing the antistatic hard coat paint of the present invention.

  The molded article of the present invention is characterized by having the antistatic hard coat film of the present invention on the surface of a resin molded article.

  According to the present invention, by using an antistatic hard coat paint containing an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound, unevenness hardly occurs when it is formed into a coating film, transparency, A coating film excellent in scratch resistance and antistatic properties can be obtained.

  In addition, since the antistatic hard coat film of the present invention is formed from the above antistatic hard coat paint, the coated member such as a resin molded body is protected from scratches and dust without changing its color. Can do.

  Further, since the molded article of the present invention has the antistatic hard coat film on the surface of the resin molded article, the molded article is excellent in scratch resistance and antistatic property without changing the color of the resin molded article. It can be.

  Hereinafter, embodiments of each component will be described.

  First, the antistatic hard coat paint of the present invention will be described. The antistatic hard coat paint of the present invention comprises an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound.

  The ionizing radiation curable resin composition is used as a resin component for imparting scratch resistance to a coating film when it is formed into a coating film. As such an ionizing radiation curable resin composition, a photopolymerizable prepolymer that can be cross-linked and cured by irradiation with ionizing radiation (ultraviolet rays or electron beams) can be used. As the photopolymerizable prepolymer, An acrylic prepolymer having two or more acryloyl groups in one molecule and having a three-dimensional network structure by crosslinking and curing is particularly preferably used. As the acrylic prepolymer, urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate and the like can be used, and can be appropriately selected according to the type and application of the member to be coated. These acrylic prepolymers can be used alone, but it is preferable to add a photopolymerizable monomer in order to impart various performances such as improvement of cross-linking curability and adjustment of curing shrinkage.

  As photopolymerizable monomers, monofunctional acrylic monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, butoxyethyl acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol One kind of bifunctional acrylic monomer such as diacrylate, polyethylene glycol diacrylate, hydroxypivalate ester neopentyl glycol diacrylate, etc., or polyfunctional acrylic monomer such as dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate or the like Two or more are used.

  In addition to the above-mentioned photopolymerizable prepolymer and photopolymerizable monomer, it is preferable to use additives such as a photopolymerization initiator and a photopolymerization accelerator when used by being cured by irradiation with ultraviolet rays.

  Examples of the photopolymerization initiator include acetophenone, benzophenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α-acyloxime ester, thioxanthone and the like.

  Further, the photopolymerization accelerator can reduce the polymerization obstacle due to air at the time of curing and increase the curing speed. For example, p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, and the like. can give.

  As the resin component, in addition to the ionizing radiation curable resin composition as described above, other resins such as thermoplastic resins and thermosetting resins may be used as long as the effects of the present invention are not impaired. Good.

  Next, the lithium salt compound is used as a component for imparting antistatic properties to the coating film when it is formed into a coating film. Thus, in this invention, since the electroconductive fine particles are not used as a component for providing an antistatic property to a coating film, the coating film at the time of coating-film can be excellent in transparency. . Further, for example, even when it is used on the surface of a resin molded body and subjected to bending by heating, the antistatic property is not lowered. Unlike the case where a surfactant type antistatic agent such as a quaternary ammonium salt is used, it can be excellent in sustainability without depending on the ambient humidity. Further, when the resin component is cured, it does not become a cause of inhibition of curing, and the scratch resistance is not lowered.

  Examples of such lithium salt compounds include lithium chloride, lithium hydroxide, lithium bis (trifluoromethanesulfonyl) imide, lithium tris (trifluoromethanesulfonyl) methane, lithium trifluoromethanesulfonate, and compounds containing these.

  Since the lithium content in such a lithium salt compound varies depending on the thickness of the coating film when it is formed into a film, it cannot be generally stated. It is preferable that the content be not less than 01% by weight, more preferably not less than 0.02% by weight, and the upper limit is preferably not more than 0.5% by weight, more preferably not more than 0.1% by weight. By setting it to 0.01% by weight or more, sufficient antistatic properties can be imparted to the coating film when it is made into a coating, and by setting it to 0.5% by weight or less, the surface hardness of the coating film is maintained. can do.

  Next, the polyether-modified compound is used as a component for improving antistatic properties, and as a component for improving leveling properties and making it difficult to cause unevenness when formed into a coating film. Examples of the polyether-modified compounds include polyether-modified silicones and perfluoroalkylethylene oxide adducts. Among these, polyether-modified silicones are preferably used from the viewpoint of easy handling and excellent leveling properties. The reason why the antistatic effect is dramatically improved by using such a polyether-modified compound as compared with the case where it is not used or when other leveling agent is used is not necessarily clear. This is probably because the coordinated field of lithium ions is stabilized by the oxygen atoms contained and the mass transfer of lithium is performed quickly.

  The content of such a polyether-modified compound is preferably 0.01% by weight or more, more preferably 0.05% by weight or more as a lower limit in the coating film when it is formed into a film, It is preferably 1% by weight or less, more preferably 0.5% by weight or less. By setting it as 0.01 weight% or more, sufficient antistatic property can be provided to the coating film at the time of forming into a coating film, and leveling property can also be improved. By setting it to 1% by weight or less, it is possible to obtain a good coating film appearance and to prevent deterioration of physical properties such as surface hardness.

  The antistatic hard coat paint of the present invention as described above is dissolved in the photopolymerizable prepolymer and the photopolymerizable monomer to form a solvent-free paint, or diluted with a diluting solvent such as an organic solvent to obtain an organic solvent paint. Also good. In addition, such an antistatic hard coat paint of the present invention is, as necessary, a lubricant, a colorant, a pigment, a dye, a fluorescent brightener, a flame retardant, an antibacterial agent, as long as the effects of the present invention are not impaired. Additives such as additives, fungicides, UV absorbers, light stabilizers, heat stabilizers, antioxidants, plasticizers, leveling agents, flow regulators, antifoaming agents, dispersants, storage stabilizers, crosslinkers, etc. It may be added.

  Such an antistatic hard coat paint of the present invention includes the above-mentioned ionizing radiation curable resin composition, a lithium salt compound, a polyether-modified compound, a dilution solvent added as necessary, other resin components, and additions An antistatic hard coat paint can be obtained by mixing or dissolving or dispersing an agent or the like.

  Such an antistatic hard coat paint of the present invention is applied to a member to be coated such as a resin molded body and irradiated with ionizing radiation to be cured, whereby the surface of the member to be coated is transparent, scratch-resistant, charged. A coating film excellent in prevention can be formed.

  Next, the antistatic hard coat film of the present invention will be described. The antistatic hard coat film of the present invention is formed by applying and curing the above-described antistatic hard coat paint of the present invention on a member to be coated.

  Further, the antistatic hard coat film of the present invention formed from the above antistatic hard coat paint is obtained by applying the above antistatic hard coat paint to a conventionally known coating method such as a bar coater, a die coater, a blade coater, a spin coater. Apply directly to the parts to be coated, such as resin moldings, glass plates, etc. that are to be given scratch resistance and antistatic properties by coater, roll coater, gravure coater, flow coater, dip coater, spray, screen printing, brush, etc. And it can produce by making it dry as needed and irradiating with ionizing radiation and hardening.

  As a method of irradiating with ionizing radiation, ultraviolet rays in a wavelength region of 100 nm to 400 nm, preferably 200 nm to 400 nm emitted from an ultra high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, etc. It can be performed by irradiating an electron beam having a wavelength region of 100 nm or less emitted from a curtain type electron beam accelerator.

  The thickness of the antistatic hard coat film is not particularly limited, but is about 1 μm to 50 μm, preferably about 2 μm to 30 μm, and more preferably about 3 μm to 15 μm. By setting the thickness of the antistatic hard coat film to 1 μm or more, a film having excellent scratch resistance can be obtained, and by setting the thickness to 50 μm or less, the strength of warping of the resin molded body due to curing shrinkage can be reduced. Further, it is possible to prevent a decrease in surface hardness due to uncured resin components.

  Next, the molded product of the present invention will be described. The molded article of the present invention has the above-described antistatic hard coat film of the present invention on the surface of a resin molded article.

  The shape of the resin molded body may be any thickness such as “film”, “sheet”, “plate”, etc., and has a three-dimensional curved surface, for example, with irregularities on the surface. It may be of a shape.

  The type of resin of the resin molded body is not particularly limited, but in the case of a film or sheet, for example, those made of resins such as acrylic, polycarbonate, polyvinyl chloride, polyester, polypropylene, polyethylene, acetylcellulose, and cycloolefin are listed. In the case of a plate or the like, one made of a resin such as acrylic, polycarbonate, polyvinyl chloride or the like can be used. In order to improve the adhesion with the antistatic hard coat paint of the present invention on the surface of the resin molded body, an easy adhesion treatment such as plasma treatment, corona discharge treatment, deep ultraviolet irradiation treatment, formation of an undercoat easy adhesion layer, etc. May be applied.

  The molded body of the present invention is produced by forming the antistatic hard coat paint of the present invention on such a resin molded body by forming the antistatic hard coat film of the present invention in the same manner as described above. Can do.

  Since the molded body of the present invention has the above-described antistatic hard coat film of the present invention on the surface of the resin molded body, it is excellent in transparency, scratch resistance and antistatic properties. Further, unlike those having antistatic properties due to conductive fine particles, the antistatic properties are good even after thermoforming such as bending. Therefore, the molded article of the present invention is suitable for use as an optical member that requires transparency, scratch resistance, and antistatic properties, a transparent material for image display such as a display screen, and the like. It can be used for applications such as wall and floor structural materials, window materials for machines installed in the room, and electronic parts of machinery used in rooms such as dust-free rooms (clean rooms).

  Hereinafter, the present invention will be described in more detail based on examples. In this example, “parts” and “%” are based on weight unless otherwise specified.

[Example 1]
The antistatic hard coat paint of the following formulation was mixed to prepare the antistatic hard coat paint of Example 1. Next, the antistatic hard coat paint of Example 1 was applied to one surface of a polyester film (Cosmo Shine A4300: Toyobo Co., Ltd.) having a thickness of 125 μm as a resin molded body by the bar coater method, and then dried. The antistatic hard coat film of Example 1 having a thickness of 4 μm was formed by irradiating ultraviolet rays with a mercury lamp, and the antistatic hard coat film (molded body) of Example 1 was produced.

  The lithium salt compound a in the formulation was pentaerythritol triacrylate containing 20% lithium bis (trifluoromethanesulfonyl) imide, and the polyether-modified compound a was polyether-modified silicone.

<Prescription of Antistatic Hard Coat Paint of Example 1>
・ Ionizing radiation curable resin composition (solid content: 100%) 50 parts (urethane acrylate) (U-6LPA: Shin-Nakamura Chemical Co., Ltd.)
-Photopolymerizable monomer (solid content: 100%) 45 parts (dipentaerythritol hexaacrylate)
(A-DPA: Shin-Nakamura Chemical Co., Ltd.)
-Lithium salt compound a (solid content 100%) 5 parts (PETA-20R: Sanko Chemical Co., Ltd.)
Polyether modified compound a (solid content 100%) 0.1 part (Paintad 29: Toray Dow Corning Silicone)
・ Photopolymerization initiator 3 parts (Irgacure 184: Ciba Specialty Chemicals)
・ Propylene glycol monomethyl ether 150 parts

[Example 2]
In the antistatic hard coat paint of Example 1, the lithium salt compound a is a lithium salt compound b (trimethylolpropane triacrylate containing 20% lithium tris (trifluoromethanesulfonyl) methane, solid content 100%, TMPTA-20T: Example 1 except that the polyether-modified compound a was changed to a polyether-modified compound b (perfluoroalkylethylene oxide adduct, solid content 100%, MegaFac F142D: Dainippon Ink and Chemicals). In the same manner as described above, an antistatic hard coat paint, an antistatic hard coat film, and an antistatic hard coat film (molded body) of Example 2 were produced.

[Comparative Example 1]
The antistatic hard coat paint and antistatic hard coat of Comparative Example 1 were the same as Example 1 except that the antistatic hard coat paint of Example 1 was changed to the antistatic hard coat paint of the following formulation. A film and an antistatic hard coat film (molded product) were produced.

<Prescription of Antistatic Hard Coat Paint of Comparative Example 1>
・ Ionizing radiation curable resin composition 33 parts (solid content 80%) (urethane acrylate)
(Unidic 17-813: Dainippon Ink & Chemicals, Inc.)
-Conductive fine particles (tin dioxide-antimony pentoxide) 104 parts-Photopolymerization initiator 0.8 parts (Irgacure 184: Ciba Specialty Chemicals)
・ Propylene glycol monomethyl ether 128 parts ・ Toluene 385 parts

[Comparative Example 2]
The antistatic hard coat paint and antistatic hard coat of Comparative Example 2 were the same as Example 1 except that the antistatic hard coat paint of Example 1 was changed to the antistatic hard coat paint of the following formulation. A film and an antistatic hard coat film (molded product) were produced.

<Prescription of Antistatic Hard Coat Paint of Comparative Example 2>
・ Ionizing radiation curable resin composition (solid content: 100%) 50 parts (urethane acrylate) (U-6LPA: Shin-Nakamura Chemical Co., Ltd.)
・ Photopolymerizable monomer (solid content: 100%) 40 parts (dipentaerythritol hexaacrylate)
(A-DPA: Shin-Nakamura Chemical Co., Ltd.)
・ Quaternary ammonium salt (solid content 50%) 20 parts (Blemmer QA: NOF Corporation)
・ Photopolymerization initiator 3 parts (Irgacure 184: Ciba Specialty Chemicals)
・ Propylene glycol monomethyl ether 150 parts

[Comparative Example 3]
In the same manner as in Example 1 except that the polyether-modified compound a was not added in the antistatic hard coat paint of Example 1, the antistatic hard coat paint, antistatic hard coat film of Comparative Example 3, Then, an antistatic hard coat film (molded product) was produced.

[Comparative Example 4]
In the same manner as in Example 1 except that the polyether-modified compound a was changed to 0.4 part of polyester-modified silicone (solid content 25%, BYK-370: BYK Chemie) in the antistatic hard coat paint of Example 1. The antistatic hard coat paint, the antistatic hard coat film, and the antistatic hard coat film (molded body) of Comparative Example 4 were produced.

[Comparative Example 5]
In the same manner as in Example 1 except that the polyether-modified compound a was changed to 0.5 part of an acrylic polymer (solid content 52%, BYK-355: Big Chemie) in the antistatic hard coat paint of Example 1. Thus, an antistatic hard coat paint, an antistatic hard coat film, and an antistatic hard coat film (molded article) of Comparative Example 5 were produced.

[Comparative Example 6]
In the antistatic hard coat paint of Example 1, the polyether-modified compound a was changed to 0.5 part of aminoethylaminopropyltrimethoxysilane (solid content 50%, Paintad A: Toray Dow Corning Silicone). In the same manner as in Example 1, an antistatic hard coat paint, an antistatic hard coat film, and an antistatic hard coat film (molded body) of Comparative Example 6 were produced.

[Comparative Example 7]
In the same manner as in Example 1, except that the polyether-modified compound a was changed to 1 part of fluorosiloxane (solid content 5%, Paintad 7: Toray Dow Corning Silicone) in the antistatic hard coat paint of Example 1. Thus, an antistatic hard coat paint, an antistatic hard coat film, and an antistatic hard coat film (molded article) of Comparative Example 6 were produced.

  The antistatic hard coat films obtained in Examples and Comparative Examples were evaluated for coating film unevenness, transparency, scratch resistance, antistatic properties, and humidity dependency of antistatic properties. The evaluation results are shown in Table 1.

(1) Evaluation of unevenness of coating film The antistatic hard coat film of the antistatic hard coat film obtained in Examples and Comparative Examples was visually evaluated to determine whether unevenness occurred. In the evaluation, “◎” indicates that there was no unevenness at all, and “◯” indicates that a slight undulation occurred, and “×” indicates that a slight undulation occurred.

(2) Evaluation of transparency First, the haze of the polyester film of Example 1 was measured using a haze meter (NDH2000: Nippon Denshoku) based on JIS K7136: 2000. Next, the haze of the antistatic hard coat film obtained in Examples and Comparative Examples was measured, and the difference from the haze of the polyester film was less than 1% was “◯”, which was 1% or more. "X" was used. The surface of each antistatic hard coat film on which light was incident was a surface having an antistatic hard coat film.

(3) Evaluation of scratch resistance The surface having the antistatic hard coat film of the antistatic hard coat film obtained in the Examples and Comparative Examples was prepared by using # 0000 steel wool and 1 kg of area 1 cm ² . The sample was reciprocated 10 times with a load, and a sample in which no scratch was visually confirmed was designated as “◯”, and a sample in which scratch was confirmed was designated as “x”.

(4) Evaluation of antistatic properties The antistatic hard coat films obtained in Examples and Comparative Examples were cut into a size of 10 cm × 10 cm and left in an environment of 23 ° C. and 50% RH for 48 hours. surface resistance meter surface resistivity (digital multimeter ohmmeter: HEWLETT · PACKARD Co.) was measured using the one measurement value less than 1 × 10 ¹² Ω "○", in 1 × 10 ¹⁴ Ω or more What was there was taken as "x".

(5) Evaluation of humidity dependency of antistatic property The humidity dependency of the antistatic property was evaluated for the antistatic hard coat films of Examples and Comparative Examples 1 and 2 used in (4). First, after leaving it to stand in an environment of 23 ° C. and 20% RH for 48 hours, the surface resistivity was measured using the above-mentioned surface resistance meter. Next, after leaving it in an environment of 23 ° C. and 80% for 48 hours, the surface resistivity was measured. The measurement value was 10 ² Ω or less as “◯”, and the measurement value width was 10 ³ Ω or more as “X”.

  As is clear from Table 1, the antistatic hard coat film of the example is an antistatic hard coat film in which the antistatic hard coat film contains an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound. Since it was formed from a coating material, the antistatic hard coat film was excellent in transparency, scratch resistance, antistatic property and humidity dependency without causing unevenness.

  On the other hand, since the antistatic hard coat film of Comparative Example 1 contained conductive fine particles, the antistatic hard coat film was inferior in transparency and scratch resistance as compared with Examples. Further, the antistatic hard coat paint of Comparative Example 1 was inferior in leveling compared to the Examples, and unevenness occurred when the antistatic hard coat film was formed.

  In addition, the antistatic hard coat film of Comparative Example 2 is an antistatic hard coat film containing a quaternary ammonium salt and having low compatibility with the resin component. When it was set as the coat film, it became inferior to transparency compared with the Example. In addition, since the inhibition of curing occurred when forming the antistatic hard coat film, the scratch resistance was low. Further, the antistatic property was evaluated excellent in an environment of 23 ° C. and 50% RH, but the humidity dependency was high, and a stable antistatic property could not be obtained.

  In Comparative Example 3, the antistatic hard coat film is formed from an ionizing radiation curable resin composition and an antistatic hard coat paint containing a lithium salt compound, and does not contain a polyether-modified compound. Therefore, the antistatic property was inferior to that of the example. In addition, the antistatic hard coat paint of Comparative Example 3 was inferior in leveling compared to the examples, and unevenness occurred when the antistatic hard coat film was formed.

  The antistatic hard coat film of Comparative Examples 4 to 7 is an antistatic hard coat paint containing a leveling agent in which the antistatic hard coat film is not an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound. Therefore, the antistatic hard coat film was excellent in transparency and scratch resistance without causing unevenness, but does not contain a polyether-modified compound. The antistatic property was inferior compared with that.

Claims (3)

  An antistatic hard coat paint comprising an ionizing radiation curable resin composition, a lithium salt compound, and a polyether-modified compound.   An antistatic hard coat film formed by applying and curing the antistatic hard coat paint according to claim 1.   A molded body comprising the antistatic hard coat film according to claim 2 on the surface of a resin molded body.