JP3504338B2 - Radiation curable coating composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-curable coating composition, and more particularly, to an excellent coating composition for various transparent plastic films, plastic plates and glass plates. The present invention relates to a radiation-curable coating composition that imparts scratch resistance, chemical resistance, and anti-glare properties. 2. Description of the Related Art Conventionally, radiation-curable coating compositions which are easily cured by irradiation with radiation such as ultraviolet rays or electron beams are known, and the above-mentioned coating compositions are made of metal, glass, plastic, wood and other articles. Widely used as a protective and decorative paint. Recently, a polarizing film material such as a triacetate film has been used as a liquid crystal display, and ultraviolet light is applied to the film surface in order to impart and improve such abrasion resistance, chemical resistance and anti-glare properties of such an optical film. It is known to provide a cured coating film made of a curable resin and further use a composition in which various silicas are dispersed and blended in the coating film. For example, it can be found in JP-B-63-40282, JP-B-4-65095, and JP-A-5-162261. [0003] For the purpose of imparting the scratch resistance, chemical resistance and anti-glare properties of the polarizing film as a liquid crystal display, the film described above is cured with the composition described in the above publication. Those with a coating film are satisfactory in abrasion resistance, but the surface containing untreated or inorganic-treated silica is whitened due to chemical resistance, and the wax treatment type of organic treatment is not sufficient in surface coating For this reason, silica is whitened and has poor practicality with the same chemical resistance as untreated silica, and surface reaction-treated silica such as alkoxide compounds, silane coupling agents, and chlorosilanes are disclosed in JP-B-62-21815, JP-B-2-60696. As disclosed in Japanese Patent Application Laid-Open No. H10-209, the chemical resistance is excellent, but the transparency is good, so that the anti-glare effect is poor and not all are sufficiently satisfied. Thus, the present inventors have conducted intensive studies to obtain a radiation-curable paint that simultaneously satisfies the abrasion resistance, chemical resistance, and anti-glare properties. As a result, the radiation-curable paint is blended with a specific hydrophobic precipitated silica. As a result, they have found that good results can be obtained, and have reached the present invention. Accordingly, it is an object of the present invention to provide a radiation-curable coating material which, when applied to a polarizing film or the like, can provide a coating having excellent scratch resistance, chemical resistance, anti-glare properties and the like. [0004] The above object is achieved by the present invention described below. That is, the present invention provides a liquid crystal containing 0.1 to 20% by weight of a hydrophobic precipitated silica obtained by a reaction between a metal silicate and a mineral acid as a main component of a filler in a radiation-curable resin.
Polyethylene terephthalate film or liquid crystal
In the radiation curable coating composition for coating an acetate film, the hydrophobic precipitated silica is (a) a specific surface area of 50 to 500 m ² / g by a BET method, and (b) an average particle size of primary particles of 15 to 500 μm according to an electron micrograph.
250 mμ (c) Average particle size of secondary particles 5 μm or less by light transmission type particle size distribution measurement (solvent: ethanol) and maximum particle size 15 μm or less of secondary particles (d) Weight loss from room temperature to 150 ° C. by thermogravimetric analysis 3.0 % Or less at room temperature to 350 ° C 4.0%
The following (e) of a 4% suspension slurry (water / ethanol = 1/1)
and a pH9.0~12.0 (f) dibutylamine adsorption 5 mg-mol / kg or less (g) water repellency 30min or more, the radiation curable coating
The coating of the paint composition is 15 drops after 3N-NaOH is dropped on the surface.
After leaving it for a minute, wipe it off and observe the surface condition.
Liquid crystal display that is not whitened.
Polyethylene terephthalate film or triace for liquid crystal
It is a radiation curable coating composition for coating a tate film . Next, the present invention will be described in more detail with reference to preferred embodiments. The radiation-curable resin composition used in the present invention is a known material, and is composed of a radiation-curable resin, a photopolymerization initiator, and other optional components. The radiation-curable resin is a relatively low-molecular-weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, or the like having a relatively polymerizable unsaturated double bond in its molecular structure. Oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols such as acrylates and methacrylates, and addition polymerizable compounds such as styrene, methylstyrene, divinylbenzene, and acrylic acid (or methacrylic acid) esters, and these components are used alone. Or it is contained as a mixture. In addition, as other examples of the radiation curable resin, cationic polymerization type vinyl ethers and epoxy resins can be used in the same manner as the above-mentioned radical polymerization type. These cationic polymerization types are
For example, a Lewis acid is generated by radiation using a photosensitive catalyst which is an aryldiazonium salt of a halogenide, and vinyl ethers such as vinyl-2-ethylhexyl ether, vinyl decyl ether and vinyl allyl ether, or mixtures thereof, and 1,2 -Epoxycyclohexane, 1,2-epoxy-4- (epoxyethyl) cyclohexane, dichloropentadienedioxide, sorbitol polyglycidyl ether, 2,2'-bis [P-
Epoxy resins such as (2,3-epoxy) phenyl] propane or a mixture thereof are cationically polymerized. In the present invention, as these radiation-curable resins, about 5 to 100% by weight of triacrylate,
It is desirable to use trifunctional or higher polyacrylates such as trimethacrylate, sorbitol triglycidyl ether, polymethacrylate or polyepoxide. When the content of such polyacrylates is 5% by weight or less, a coating having a sufficient surface hardness is required. Cannot be formed. The sensitizer required when using ultraviolet rays as radiation is a compound that generates free radicals by the energy of ultraviolet rays, such as carbonyl compounds such as benzoin, benzophenone or their esters, and organic peroxides such as benzoyl peroxide. Examples include oxides, azo compounds such as azobisisobutyronitrile, and sulfur compounds such as diphenyl disulfide. In the case of the cationic polymerization type, a compound represented by a complex halogenide aryldiazonium salt such as 2,5-diethoxy-4- (p-tolylthio) benzenediazonium hexafluorophosphate is used. Other optional components include small amounts of organic solvents, coloring agents such as dyes and pigments, waxes and other various additives. The radiation-curable coating composition composed of the above components is already known, and is used by changing the type and the ratio of the components according to the use. For example, when the application is a paint as in the present invention and ultraviolet rays are used, the sensitizer is preferably used in a ratio of about 1 to 10 parts by weight per 100 parts by weight of the radiation-curable resin. The viscosity of the paint is preferably adjusted to about 5 to 1000 cp using a liquid oligomer, monomer or organic solvent. Such a conventional radiation-curable resin composition is applied to the surface of a substrate and irradiated with an electron beam or ultraviolet ray having an appropriate energy, and is cured in several seconds to several minutes to form a glossy and tough film. be able to. Next, the hydrophobic precipitated silicic acid used in the present invention, which mainly characterizes the present invention, refers to secondary particles of secondary particles obtained by reacting an alkali metal silicate and a mineral acid by a light transmission type particle size distribution measurement. Average particle size 5μ or less Loss on drying after 105 ° C for 1 hour 4.0% or more NaO content 0.5 to 3.0% Preferably, average particle size of secondary particles by light transmission type particle size distribution measurement 3μ or less 105 ° C for 1 hour After drying loss 4.0 to 10.0% or more NaO content 1.0 to 2.5% 100 parts by weight of precipitated silica and 50 to 500C at 25 ° C
S, preferably a mixture of 5 parts by weight or more, preferably 5 to 15 parts by weight of a silicone oil having 50 to 100 CS
Treated at 00 to 150 ° C, preferably 120 to 150 ° C for 30 minutes or more, and then at a temperature of 250 to 300 ° C for 30 to 1
It is manufactured by baking for 20 minutes. The alkali metal silicate used in the above reaction is
Mainly sodium silicate. The main mineral acids are sulfuric acid, hydrochloric acid and phosphoric acid. Examples of the silicone oil used for treating the precipitated silica include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and methyl biphenyl silicone oil. The mixing process of the precipitated silicic acid and the silicone oil may be performed by any type of ordinary mixer, but when the fine powder and the liquid are mixed as described above, the aggregated particles due to the adhesive force of the liquid are used. It is preferable to use a mixing device that does not cause the above. Such devices include:
Examples thereof include a ball mill and a fluid mixer. Such hydrophobic precipitated silica used in the present invention can be obtained from the market under a trade name such as [nip seal, SS grade]. The present inventor has found that a radiation-curable coating composition containing such a hydrophobic precipitated silica is very effective in improving scratch resistance, chemical resistance and anti-glare properties when applied to a plastic film or the like. As we have found, this is a completely unexpected effect. The hydrophobic precipitated silica is used in an amount of 0.1 parts by weight based on 100 parts by weight of the radiation-curable resin.
５０50 parts by weight, preferably 1-20 parts by weight. In the radiation-curable coating composition of the present invention, conventionally known various additives, for example, organic solvents, plasticizers, dyes, pigments, waxes and the like are added and used as necessary in addition to the above essential components. The above radiation-curable coating composition is abrasion-resistant by being applied to various plastic films,
A film with excellent chemical resistance and good anti-glare properties can be obtained.
The radiation-curable coating composition of the present invention can be applied on a plastic film and dried to form a coating layer,
At this time, known coating methods such as a spray coating method, a gravure coating method, a roll coating method, and a bar coating method can be used. The amount of coating is adjusted to a desired film thickness in consideration of required physical properties. Examples of the plastic film used in the present invention include a polystyrene film, a polycarbonate film, a polyester film, a polyamide film, a polyethylene film, a polypropylene film, a diacetylcellulose film, a triacetylcellulose film, a polyvinyl chloride film, a polyvinylidene chloride film, Polysulfone film, polyvinylidene fluoride film, triacetyl cellulose film, polyethersulfone film, etc., are not particularly limited to these films, and may be appropriately selected from known transparent plastic films for use. Can be. When coating the film coating solution on the film surface, for example, from the viewpoint of facilitating coating and making the thickness of the coating film uniform,
The viscosity can be adjusted by adding an organic solvent such as isopropyl alcohol, toluene and ethyl acetate. In the present invention, the above film coating solution is applied on a film,
By irradiating with electron beams or ultraviolet rays of appropriate energy after heating and drying, it can be cured in several seconds to several minutes to form a tough film. Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 50 parts by weight of a polyfunctional acrylate [trade name: Kayarat DPHA, manufactured by Nippon Kayaku Co., Ltd.], polyfunctional urethane acrylate [trade name: Shikko UV1700, Nippon Synthetic Chemical Industry Co., Ltd.]
Co., Ltd.] 50 parts by weight, polymerization initiator [trade name: Darocur-1173, Nippon Ciba Geigy Co., Ltd. product] 5 parts by weight,
Hydrophobic precipitated silica [trade name: NIPSEAL SS-50B,
Nippon Silica Industry Co., Ltd.] 5 parts by weight and toluene 70 parts by weight were uniformly mixed to obtain a radiation-curable coating composition of the present invention. An appropriate amount of a diluting solvent was added to 100 parts by weight of this coating composition to make Ford Cup # 4, 20 seconds. The above-mentioned hydrophobic precipitated silica has the following physical properties. -Specific surface area by BET method: 73 m2 / g-Average particle size of primary particles: 21 mμ by electron micrograph- ² by light transmission type particle size distribution measurement (solvent: ethanol)
The average particle size of the primary particles is 1.2 μm and the maximum particle size of the secondary particles is 8 μm. The weight loss from room temperature to 150 ° C. by thermogravimetric analysis is 2.3.
% And loss from room temperature to 350 ° C. 3.3%. PH 1 of 4% suspension slurry (water / ethanol = 1/1)
1.7-Dibutylamine adsorption amount 0.0 mg-mol / kg-Water repellency 50 min Then, the above coating composition was applied to a polyethylene terephthalate film (trade name: Tetron film HP-7, a product of Teijin Limited) by a gravure coater. As a result, the cured coating film becomes 4
５5μ, and after drying the solvent, output 1
Irradiation was performed once at a line speed of 20 m / min using two 60 W / cm ultraviolet lamps (ozone generating type) to cure the coating. The physical properties are shown in Table 1. Comparative Example 1 A cured film was formed in the same manner as in Example 1 except that 5 parts by weight of untreated silicic anhydride [trade name: Cycilia # 350, manufactured by Fuji Silysia Chemical Ltd.] was used instead of hydrophobic precipitated silica. A polyethylene terephthalate film was obtained. The physical properties are shown in Table 1. Comparative Example 2 Wet method hydrous silicic acid (amorphous) instead of hydrophobic precipitated silicic acid [trade name: Nipseal E-220A, Nippon Silica Industry Co., Ltd.]
Product] A polyethylene terephthalate film having a cured film was obtained in the same manner as in Example 1 except that 5 parts by weight was used. The physical properties are shown in Table 1. Example 2 50 parts by weight of isocyanuric triacrylate [trade name: ARONIX M-315, manufactured by Toagosei Chemical Industry Co., Ltd.]
Trimethylolpropane trimethacrylate 50 parts by weight, hydrophobic precipitated silica [trade name: Nipsil SS-50]
B, product of Nippon Silica Industry Co., Ltd.] 5 parts by weight, toluene 70
The parts by weight were uniformly mixed to obtain a radiation-curable resin composition of the present invention. An appropriate amount of a diluting solvent was added to 100 parts by weight of the coating composition to obtain Ford Cup # 4 for 20 seconds. Next, this coating composition was applied to a glass plate which had been subjected to a primer treatment with a butyral resin by a reverse roll. The coating film is irradiated with an electron beam (EB) (5 Mra).
d) to cure the coating. The physical properties are shown in Table 1. Comparative Example 3 Silica treated organically in place of hydrophobic precipitated silicic acid [trade name: Cycilia # 256, manufactured by Fuji Silysia Chemical Ltd.]
A glass plate having a cured coating was obtained in the same manner as in Example 2 except that 5 parts by weight was used. The physical properties are shown in Table 1. Comparative Example 4 Isocyanuric triacrylate [trade name: ARONIX M-315, product of Toagosei Chemical Industry Co., Ltd.] 40 parts by weight,
60 parts by weight of polyethylene glycol diacrylate, organically treated silicic anhydride [trade name: Cycilia # 256, manufactured by Fuji Silysia Chemical Ltd.], and 70 parts by weight of toluene were uniformly mixed to obtain a radiation-curable resin composition. An appropriate amount of a diluting solvent was added to 100 parts by weight of the coating composition to obtain Ford Cup # 4 for 20 seconds. Next, this coating composition was applied to a glass plate which had been subjected to a primer treatment with a butyral resin by a reverse roll. The coated film was irradiated with electron beam (EB) (5 Mrad) to cure the film. The physical properties are shown in Table 1. Example 3 Urethane acrylate [trade name: Beam Set KU-5]
75, Arakawa Chemical Industry Co., Ltd.] 100 parts by weight, polymerization initiator [Irgacure-184, Nippon Ciba Geigy Co., Ltd. product] 5 parts by weight, hydrophobic precipitated silicic acid [trade name: NIPSEAL SS-50B, Nippon Silica Industry ( 5 parts by weight and 70 parts by weight of toluene were uniformly mixed to obtain a radiation-curable resin composition of the present invention. An appropriate amount of a diluting solvent was added to 100 parts by weight of the coating composition to obtain Ford Cup # 4 for 20 seconds. Then, triacetate film [trade name: TAC]
Film, Fuji Photo Film Co., Ltd.], and the above coating composition was cured with a microgravure coater to form a cured film of 4%.
５5μ, and after drying the solvent, output 1
Irradiation was performed once at a line speed of 20 m / min using two 60 W / cm ultraviolet lamps (ozone generating type) to cure the coating. The physical properties are shown in Table 1. Comparative Example 5 A cured coating was obtained in the same manner as in Example 3 except that 5 parts by weight of an amorphous silica treated with an organic substance [trade name: Matt Agent OK-607, a product of Degussa Co., Ltd.] was used instead of hydrophobic precipitated silica. A triacetate film was obtained. The physical properties are shown in Table 1. Example 4 Polyfunctional oligoester acrylate [trade name: ARONIX M-7100, manufactured by Toagosei Chemical Industry Co., Ltd.] 70 parts by weight, polyfunctional urethane acrylate [trade name: Shikko UV]
1700, Nippon Synthetic Chemical Industry Co., Ltd. product] 30 parts by weight, polymerization initiator [trade name: Darocur-1173, Nippon Ciba Geigy Co., Ltd. product] 5 parts by weight, hydrophobic precipitated silica [trade name:
Nip Seal SS-50B, Nippon Silica Industry Co., Ltd. product]
5 parts by weight and 70 parts by weight of a diluent (xylene / butyl acetate / methyl isobutyl ketone / n-butanol = 2/2/2/1 mixed solvent) were uniformly mixed to obtain a radiation-curable coating composition of the present invention. . An appropriate amount of a diluting solvent was added to 100 parts by weight of the coating composition to obtain Ford Cup # 4 for 20 seconds. Next, the coating composition obtained in Example 4 was applied to polymethyl methacrylate [trade name: Acrylite E, manufactured by Mitsubishi Rayon Co., Ltd.] by spraying. The solvent was dried in a 70 ° C. far-infrared heating zone for 3 minutes. The physical properties are shown in Table 1. [Table 1] The physical properties were measured as shown in Table 1 as follows. -Evaluation of antiglare property The following four optical characteristics were measured and evaluated. As evaluation criteria, the total light transmittance is as high as possible and the gloss (60
(Degree gloss, 20 degree gloss), the lower the better. Further, the scattered light transmittance was measured to determine the haze degree, and the final evaluation of the antiglare property (appearance) was made in consideration of the balance with the gloss. Total light transmittance (%) Haze degree (scattered light transmittance / total light transmittance) 60 degrees gloss 20 degrees gloss / scratch resistance Before and after 100 round trips with steel wool 0000 while applying a load of 1 kg / cm ^{2 on} the coating film Comparative evaluation of haze degree. -Pencil scratching test According to JIS K 5400 8.4.1. -Chemical resistance Each chemical was dropped on the coating film surface and wiped off, and the state of change on the surface was observed. 3N-NaOH: left for 15 minutes after dropping Other solvents: left for 10 hours after dropping When used as a paint for surface protection and surface decoration, a coating with excellent scratch resistance, chemical resistance, and anti-glare properties can be formed as compared with conventional paints of the same type.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Nobuo Takezawa 1-7-6, Bakurocho, Nihonbashi, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (56) References JP-A-58-208124 (JP, A) JP-A-5-162261 (JP, A) JP-A-1-105573 (JP, A) JP-A-62-144943 (JP, A) JP-A-59-151109 (JP, A) JP-A-6-157788 ( JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A23D 5/00

Claims (1)

(57) [Claims 1] A hydrophobic curable silica obtained by a reaction between a metal silicate and a mineral acid as a main component of a filler is added to a radiation curable resin in an amount of 0.1%.
Polyethylene terephthalate for liquid crystal containing 1 to 20% by weight
Film or triacetate film for liquid crystal
In the radiation curable coating composition for use , the above-mentioned hydrophobic precipitated silica is (a) a specific surface area of 50 to 500 m ² / g by the BET method, and (b) an average particle size of primary particles of 15 to 500 by an electron micrograph.
250 mμ (c) Average particle size of secondary particles 5 μm or less by light transmission type particle size distribution measurement (solvent: ethanol) and maximum particle size 15 μm or less of secondary particles (d) Weight loss from room temperature to 150 ° C. by thermogravimetric analysis 3.0 % Or less at room temperature to 350 ° C 4.0%
The following (e) of a 4% suspension slurry (water / ethanol = 1/1)
and a pH9.0~12.0 (f) dibutylamine adsorption 5 mg-mol / kg or less (g) water repellency 30min or more, the radiation curable coating
The coating of the paint composition is 15 drops after 3N-NaOH is dropped on the surface.
After leaving it for a minute, wipe it off and observe the surface condition.
Liquid crystal display that is not whitened.
Polyethylene terephthalate film or triace for liquid crystal
A radiation-curable coating composition for coating a tate film .