• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.535-540
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• 2011

Organic-inorganic hybrid coating solutions were prepared starting from colloidal silica, lanthanum nitrate and ${\gamma}$-glycidoxypropyl trimethoxysilane by the sol-gel method. Also, spiropyran-doped hard coating solutions were prepared by mixing the spiropyran solution, obtained after dissolving spiropyran dye into tetrahydrofuran solvent, with the organic-inorgnic hybrid coating solutions. The spiropyran-doped hard coating solutions were applied as a thin layer to polycarbonate sheets, and their photochromic properties were investigated. The effect of amount of colloidal silica added into the coating solutions was investigated on the photochromic properties of coating films. Both decoloration rate and pencil hardness of the coating films were increased with increasing the amounts of colloidal silica.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.762-769
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• 2015

The titania ($TiO_2$) nanoparticles with a diameter 2?3 nm were synthesized by controlling hydrolysis of titanium tetraisopropoxide (TTIP) in acid solution. Organic-inorganic hybrid coating solutions were prepared by reacting the titania nanoparticles with 3-glycidoxypropyl trimethoxysilane (GPTMS) by the sol-gel method. The hard coating films with high refractive index were obtained by curing thermally at $120^{\circ}C$ after spin-coating the coating solutions on the polycarbonate (PC) sheets. The coating films showed high optical transparency of 90% in the visible range and exhibited a pencil hardness of 2H. Also, the refractive index at 633 nm wavelength of coating films enhanced from 1.502 to 1.584 as the weight content of titania nanoparticles in the coating solutions increased from 4% to 25%.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.388-394
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• 2014

Inorganic-organic hybrid coating solutions were synthesized using titania sol from titanium isopropoxide (TTIP) as an inorganic component and mixture of two or three types of silane coupling agents, such as methacryloxypropyl trimethoxysilane (MPTMS), aminopropyl triethoxysilane (APS), glycidoxypropyl trimethoxysilane (GPTMS) and vinyltriethoxysilane (VTES) as an organic component. The hard coating films were obtained by spin-coating on the polycarbonate sheets and curing the inorganic-organic hybrid coating solutions. The coating films made from the mixture of two types of silane coupling agents showed poor pencil hardness and adhesion, while those from the mixture of three types of silane coupling agents exhibited an improved pencil hardness of 2H~4H and adhesion of 5B. The refractive indexes of coating films were increased from 1.56 to 1.63 at 550 nm by increasing the content of titania sols from 20 to 30 g.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.87-92
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• 2017

Poly(urethane acrylate) siloxane oligomers with Interpenetrating polymer networked nanoparticles were prepared to synthesize hard coating solution by reaction with isophorone diisocyanate(IPDI) of 1, 2, 3, 4 phr. The structures and molecular weights of the synthesized solutions were characterized by IR spectroscopy and gel permeation chromatography, respectively. In the cross-cut test for the adhesion, all the solutions showed good adhesion of 5B regardless of the content of IPDI and film thickness. The addition of 1 phr IPDI resulted in the best pencil hardness. The IPDI combined siloxane hard coating solution showed more flexibility than the siloxane solution. These results will yield the improvement in the siloxane solution using for plastic display plate.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.274-278
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• 2008

Hard coating solutions were prepared from glycidoxypropyl trimethoxysilane (GPTMS) and methacryloxypropyl trimethoxysilane (MPTMS) precursors with different molar ratios of 10:0, 9:1, 7:3, 5:5, 3:7, and 0:10, respectively, by the sol-gel method. The polycarbonate (PC) sheets were spin-coated, and cured at $130^{\circ}C$ for 3 h. The effect of the GPTMS:MPTMS molar ratios of the mixture was investigated on the properties of coating films. The highest pencil hardness and adhesion to PC sheets of coating films were found for solution with GPTMS:MPTMS molar ratio of 5:5. Also, the pencil hardness of coating films was increased with increasing the $H_2O$ content in the coating solutions.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.442-447
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• 2007

In order to improve the surface hardness of transparent plastic films, organic-inorganic hybrid coating solutions were synthesized by the sol-gel method. The coating solutions were prepared by adding GPTMS (glycidoxypropyl trimethoxysilane) to a colloidal silica (12 nm) suspension. PC(polycarbonate) substrates were dipped into the coating solutions and dried at room temperature for 10 min before being cured at $80^{\circ}C$ for 30 min. The effect of the solution pH and GPTMS content was investigated on the properties of coating films. The pencil hardness and adhesion to substrates of the coating films, prepared at acidic condition (pH 4), showed better properties than those at neutral or basic conditions. Also, the pencil hardness and adhesion to substrates of the coating films increased with increasing GPTMS content.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.162-168
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• 2018

UV-curable hard coating solutions were prepared by mixing organic or inorganic polysilazane with urethane acrylate. UV-cured hard coating films were also obtained by flow coating, subsequently UV-curing on polymethylmethacrylate (PMMA) sheets. The effect of types and amounts of polysilazane was investigated on properties of obtained coating films. As a result, the coatings obtained by using organic polysilazane showed a high hydrophobic property with water contact angle of $95^{\circ}$, pencil hardness of 7H and high transparency of 92% in the visible wavelength range. On the other hand, the PMMA sheets made by using inorganic polysilazane exhibited a pencil hardness of as high as 8H, good adhesion to the substrate and water contact angle of $82^{\circ}$.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.335-339
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• 2007

In order to overcome the problem of poor hardness of transparent polycarbonate (PC) sheets, organic-inorganic hybrid hard coating solutions, which show a high refractive index above 1.58, were made by the sol-gel method. These hybrid coating solutions were obtained from mixture of titanium tetraisopropoxide (TTIP), and (3-glycidoxypropyl)trimethoxysilane (GPTMS). The PC sheets were spin-coated, and cured at $120^{\circ}C$ for 2 hr. Change of refractive index in the range of 1.53-1.61 was obtained by varying the GPTMS content. The refractive index of the coated film decreased with increasing the GPTMS content, while the pencil hardness of the coated film was found to increase with increasing the GPTMS content.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.310-315
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• 2008

Organic-inorganic hybrid solutions were made using glycidoxypropyl trimethoxysilane (GPTMS) and vinyltriethoxysilane (VTES) as starting materials by sol-gel method. Photochromic coating solutions were prepared by mixing the solution of photochromic dye (spiropyran) dissolved in ethylacetate with the organic-inorganic hybrid solutions. Photochromic films were prepared on polycarbonate sheets by spin coating and cured for 2 h at $100^{\circ}C$. The resulting films exhibited a reversible color change upon irradiation with UV light from transparent to blue. The color-fading speed and pencil hardness of the coating films increased with increasing the GPTMS content in the coating solutions.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.776-782
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• 2015

$TiO_2-SnO_2$ nanoparticles with an average diameter of 3~5 nm were synthesized by hydrolysis of titanium tetraisopropoxide (TTIP) and tin chloride to depress the photocatalytic activity of $TiO_2$ nanoparticles. Organic-inorganic hybrid coating solutions were prepared by reacting the $TiO_2-SnO_2$ nanoparticles with 3-glycidoxypropyl trimethoxysilane (GPTMS) by the sol-gel method. The hard coating films with high refractive index were obtained by curing thermally at $120^{\circ}C$ after spin-coating the coating solutions on the polycarbonate (PC) sheets. The coating films from $TiO_2-SnO_2$ nanoparticles showed an improved pencil hardness of 3H compared to 2H of the coating films from $TiO_2$ nanoparticles. Besides, the refractive index of the coating films from $TiO_2-SnO_2$ nanoparticles enhanced from 1.543 to 1.623 at 633 nm as the Sn/Ti molar ratio increased from 0 to 0.5.