WO2004076566A1

WO2004076566A1 - Organic-inorganic hybrid composite, preparation thereof and anti-fogging coating composition comprising same

Info

Publication number: WO2004076566A1
Application number: PCT/KR2003/001481
Authority: WO
Inventors: Yun Ho Han; Sang Soo Oh; Jun Beom Kim; Dae Sung Lee
Original assignee: Luvantix Co., Ltd.
Priority date: 2003-02-27
Filing date: 2003-07-24
Publication date: 2004-09-10
Also published as: KR100533905B1; KR20030036304A; AU2003303974A1

Abstract

An anti-fogging coating composition comprising a novel organic-inorganic hybrid composite of the present invention is used to prepare a transparent anti-fogging coating layer having high surface hardness and improved, durable anti-fogging property.

Description

ORGANIC-INORGANIC HYBRID COMPOSITE, PREPARATION THEREOF AND ANTI-FOGGING COATING COMPOSITION COMPRISING SAME

FTPT T) OF THE TNVF.NTTON

The present invention relates to an organic-inorganic hybrid composite and a coating composition comprising same which, by photo-curing, provides a transparent anti-fogging coating layer having high surface hardness and improved anti-fogging ability.

RACKGKOTTNn OF THE TNVENTTON

Conventional anti-fogging agents such as the compositions disclosed in US

Patent Publication No. 2002/0061950A1, Korean Patent Publication No. 2000-8569 and Korean Patent No. 302,326 are based on water-soluble organic polymers, e.g., polyvinylalcohol. Coating layers formed therefrom, however, show poor durability and surface hardness under a humid condition.

In order to improve the surface hardness and anti-fogging property of a coating layer, European Patent No. 0,716,051 teaches a thermal-curable coating composition comprising a metal oxide together with an organic polymer; US Patent

No. 5,739,181, a photo-curable composition comprising an unsaturated organic material, silane and silica; and Korean Patent No. 297,952, a composition comprising a hydrophilic organic monomer having photo-curable unsaturated hydrocarbon groups, unsaturated alkoxysilane and a metal oxide. However, the silica used in the above compositions for increasing surface hardness is physically dispersed in an organic matrix, and tends to coagulate during long-term storage. Also, the physical presence of such discrete silica particles reduces the anti-fogging property of the layer. Coating layers formed using the above compositions, therefore, exhibit limited surface hardness and anti-fogging property which are inversely correlated to each other.

Accordingly, the present inventors have endeavored to develop an improved anti-fogging composition capable of providing a coating, layer having high surface hardness as well as improved anti-fogging property. SUMMARY OF THF. INVENTION

Accordingly, it is a primary object of the present invention to provide a composite which is used to form a coating layer having high surface hardness and improved, durable, anti-fogging property, and a method of preparation thereof.

It is another object of the present invention to provide an anti-fogging coating composition containing same.

In accordance with one aspect of the present invention, there is provided a method of preparing an organic-inorganic hybrid composite which comprises the steps of:

(a) reacting a polymerizable hydrophilic organic compound containing one or more terminal hydrophilic groups with a polymerizable alkoxysilane to form a hydrophilic polymer;

(b) reacting the polymer with a nano-sized silica sol to form a hydrophilic nano-sized organic-inorganic hybrid; and

(c) reacting the hybrid with a photo-curable alkoxysilane having one or more terminal unsaturated groups.

DETATT ED DESCKTPTTON OF THE TNVENTTON

The organic-inorganic hybrid composite of the present invention is a complex containing hydrophilic, UV-curable and nano-sized metal oxide moieties intimately bonded to each other.

Step (a.) : Preparation of Hydrophilic Polymer

The hydrophilic polymer that is prepared in step (a) may be an acryl polymer or a urethane polymer depending on whether the polymerizable alkoxysilane is an unsaturated alkoxysilane to be reacted with an unsaturated hydrophilic compound or an alkoxysilane isocyanate to be reacted with one of the functional groups of the hydrophilic organic compound.

(1) Preparation of acryl polymer

A hydrophilic acryl polymer may be prepared by polymerizing an organic compound containing terminal hydrophilic groups such as amine, hydroxy and thol groups, photo-curable unsaturated hydrocarbon groups and ester groups with an alkoxysilane containing one or more terminal unsaturated groups of the structure R_xSi(OR')_4-x (R is C_1-10 alkenyl, R' is C_1-10 alkyl, and x is an integer in the range of 1 to 3) in the presence of a thermal-polymerization initiator at a temperature ranging from 40 to 80 ^°C .

In this acryl polymerization, the unsaturated hydrocarbon group (-CH=CH₂) of the alkoxysilane polymerizes with the unsaturated hydrocarbon groups (-CH=CH₂) of the polymerizable hydrophilic organic compound.

Representative examples of the hydrophilic polymer include poly(ethyleneglycol) phenyl ether methacrylate, poly(ethyleneglycol) diacrylate (PEGDA), poly(propyleneglycol) dimethacrylate, poly(propyleneglycol) diacrylate (PPGDA), poly(ethyleneglycol) dimethacrylate, poly(ethyleneglycol) acrylate, poly(ethyleneglycol) methyl ether acrylate, poly(propyleneglycol) acrylate, ρoly(ethyleneglycol) phenyl ether methacrylate, poly(ethyleneglycol) 2,4,6-tris(l-phenylethyl) phenyl ether methacrylate and the like.

Examples of the polymerizable hydrophilic organic compound include 2-hydroxyethylmethacrylate (2-HEMA), 2-hydroxypropylacrylate (2-HPA), dipentaerythritol caprolacton hexa acrylate, ethoxylated (9) trimethylol propane triacrylate, ethoxylated (4) pentaerythritol tetraacrylate, ethoxylated (6) trimethylol propane triacrylate, 4-tert-butyl cyclohexyl acrylate, glycidyl vinyl benzyl ether, N,N-diglycidyl aniline, bis(4-glycidyloxyphenyl)methane, 2-(sulfoxy)ethyl methacrylate ammonium salt and the like.

Examples of the unsaturated alkoxysilane suitable for use in this reaction are (3-acryloxypropyl)methyldimethoxysilane, methacryloxypropyltrimethoxysilane (MAPTMOS), acryloxypropyltrimethoxysilane (APTMOS),

(methacryloxymethyl)phenyldimethylsilane, methacryloxypropyltris(trimethylsiloxy)silane and vinyltriethoxysilane.

The unsaturated alkoxysilane may be employed so that the amount of the unsaturated group thereof is in the range of 1 to 1.5 equivalents based on the amount of the unsaturated groups of the hydrophilic organic compound. When the amount of unsaturated alkoxysilane is more than the upper limit defined above, unreacted unsaturated groups bring about undesirable gelation and lower the stability of the composition.

The acryl polymerization may be conducted by dissolving an unsaturated alkoxysilane in a suitable solvent, adding thereto a mixture of a polymerizable hydrophilic organic compound and a thermal-polymerization initiator dissolved in the same solvent at a temperature ranging from 40 to 80 C over a period ranging from 10 to 120 min with stirring, and stirring further for a period ranging from 4 to 10 hrs. When the reaction temperature is less than 40^°C₅ the reaction is too slow, and when more than 80 ^°C , undesired gelation occurs.

As the thermal-polymerization initiator, any one of those known in the art may be used. Representative examples thereof include commercially available TRIAM-605 (diallyl chlorendate), TRIAM-606 (diallyl hexahydrophthalate), TRIAM-705 (triallyl trimellitate or triallyl 1,2,4-benzenetricarboxylate), V-30 (2-cyano-2-propylazoformamide), V-40 (l,l '-azobis(cyclohexane-l-carbonitrile)), V-50 (2,2'-azobis(2-amidinopropane)dihydrochloride), V-59 (2,2'-azobis(2-methylbutyronitrile)), V-60 (2,2'-azobisisobutyiOnitrile)), V-65 (2,2'-azobis(2,4-dimethylvaleronitrile))₅ N-70

(4-methoxy-2,4-dimethylvaleronitrile), AIBN

(2,2'-azobis(2-methylpropanenitrile)) and a mixture thereof, among which preferred areV-40, V-50, V-59, V-60, V-65, V-70 and AIBN. Said thermal-polymerization initiator may be used in an amount ranging from 0.01 to 1% by weight based on the total amount of the reactants. When the amount is less than 0.01% by weight, the reaction proceeds too slowly, and when more than 1% by weight, undesired gelation occurs.

The solvent which is used in the present invention may be any one of those known in the art, and representative examples thereof include isopropyl alcohol, diacetone alcohol, n-butanol, toluene, xylene, ethyl cellusolve, butyl cellusolve, methyl isobutyl ketone, methyl ethyl ketone, ethyl acetate and normal butyl acetate, among which preferred are isopropyl alcohol, n-butanol, toluene, ethyl cellusolve, methyl isobutyl ketone, methyl ethyl ketone and ethyl acetate. Preferably, the solvent may be used in an amount ranging from 40 to 90% by weight based on a total amount of the reactants.

(2) Preparation of urethane polymer

A hydrophilic urethane polymer may be prepared by polymerizing an organic compound containing terminal hydrophilic groups such as -NH₂, -OH and -SH with an alkoxysilane containing at least one isocyanate group in the presence of a urethane polymerization catalyst.

In this urethane polymerization, the isocyanate group (-NCO) of the alkoxysilane reacts with the hydrophilic groups, e.g., hydroxy (-OH), amine (-NH₂) and thiol (-SH), of the hydrophilic organic compound. The organic compound may be a glycol containing two or more hydroxy groups at its ends, ether-, polyester-based polyol, polyether-based caprolactone polyol, polycarbonate-based polyol or polyamine, and representative examples thereof include polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene triol, polyoxytetramethylene glycol, polyethylene adiphate, polypropylene adiphate, polybutylene adiphate, polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), ethylene diamine (EDA) and diethylene triamine (DETA).

Suitable for use in this reaction is an alkoxysilane such as y -isocyanatopropyltrimethoxysilane.

The isocyanate groups of the alkoxysilane may be employed in an amount ranging from 1 to 1.5 equivalents based on the amount of hydrophilic groups of the hydrophilic organic compound. When the amount of the isocyanate group of the alkoxysilane is less than 1 equivalent, unreacted hydrophilic groups lead to phase separation of the composition and poor abrasion resistance.

Suitable urethane polymerization catalysts include dibutyltindiraurate, dibutyltindibromide, dibutyltindichloride and l,4-diazabicyclo(2,2,2)octane, wherein dibutyltindichloride and l,4-diazabicyclo(2,2,2)octane are preferred. It may be used in an amount ranging from 0.001 to 1% by weight based on the total solid amount of reactants. When the amount is less than 0.001% by weight, the reaction proceeds too slowly, and when more than 1% by weight, undesired gelation occurs.

Representative examples of the solvent which may be used in the present invention include methyl ethyl ketone, toluene, N,N-dimethylformamide, ethyl acetate, isopropyl alcohol, acetone, tetrahydrofuran and cyclohexanone.

Preferably, the solvent may be used in an amount ranging from 5 to 95% by weight based on a total amount of the reactants.

Step (h) : Preparation of Nano-sized Organic-T organic Hybrid The hydrophilic nano-sized organic-inorganic hybrid may be prepared by hydrolyzing the hydrophilic polymer formed in step (a) and condensing with a nano-sized silica sol in the presence of a hydrolysis catalyst at a temperature ranging from 5 to 80 C₅ preferably for 2 to 30 hrs.

The silica sol may be prepared by a sol-gel reaction, or commercially available nano-sized colloidal SiO₂ particles may be used, examples of which are SNOWTEX 40 (40% SiO₂, diameter: 10-20nm, Nissan Chemical), SNOWTEX C (20% SiO₂, diameter: 10-20nm, Nissan Chemical), SNOWTEX O (20% SiO₂, diameter: 10-20nm, Nissan Chemical), MA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical), IPA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical), s LUDOX HS-40 (40% SiO₂, diameter: 12nm, Dupont), LUDOX HS-30 (30% SiO₂, diameter: 12nm, Dupont), LUDOX SM (50% SiO₂, diameter: 7nm, Dupont), LUDOX AM (30% SiO₂, diameter: 12nm, Dupont), NYACOL DP5820 (30% SiO₂, diameter: 20nm, Nyacol), NYACOL DP5480 (30% SiO₂, diameter: 50nm, Nyacol), NYACOL DP5540 (30% SiO₂, diameter: lOOnm, Nyacol), LEVASIL o 50CK/20% (20% SiO₂, diameter: 75nm, Bayer), LEVASIL 50CK/30% (30% SiO₂, diameter: 75nm, Bayer), LEVASIL 100/30% (30% SiO₂, diameter: 30nm, Bayer), LEVASIL 200/30% (30% SiO₂, diameter: 15nm, Bayer), LEVASIL 200A/30% (30% SiO₂, diameter: 15nm, Bayer) and LEVASIL 300F/30% (30% SiO₂, diameter: 9nm, Bayer), wherein preferred are SNOWTEX 40, MA-ST, IPA-ST, s LUDOX HS-40, LUDOX HS-30, LUDOX SM, LUDOX AM, NYACOL DP5820 and LEVASIL 200/30%.

Such a silica sol may be used in an amount ranging from 15 to 95% by weight based on the total amount of the reactants. When the amount is less than 15%) by weight, a coating layer with low hardness is formed, and when more than o 95% by weight, shrinkage of the coating layer occurs.

Suitable for use in this reaction are hydrolysis catalysts such as 0.001 to 1.2N HC1 and an acetic acid solution.

Step (c) : Preparation of Organic-Tnorganic Hybrid Composite 5 A hydrophilic organic-inorganic hybrid composite may be prepared by hydrolyzing and condensing the hydrophilic nano-sized organic-inorganic hybrid formed in step (b) together with an alkoxysilane containing one or more photo-curable unsaturated hydrocarbon groups in the presence of a hydrolysis catalyst at a temperature ranging from 5 to 80 C ₅ preferably for 2 to 30 hrs. 0 In this reaction, photo-curable alkoxysilane chemically bonds to the surface of silica sol of the hybrid through a sol-gel reaction.

Representative examples of alkoxysilane having photo-curable unsaturated hydrocarbon groups such as acryl, vinyl and methacryl groups include vinyltrimethoxysilane, acryloxypropyltrimethoxysilane and 5 methacryloxytrimethoxysilane, among which acryloxypropyltrimethoxysilane and methacryloxytrimethoxysilane are preferred.

The inventive hybrid may be employed in an amount ranging from 25 to 75% by weight based on the total amount of the reactants. When the amount is less than 25%o by weight, the coating layer shows low hardness and poor anti-fogging property, and when more than 75% by weight, the curing rate becomes slow.

Suitable for use in this reaction as a hydrolysis catalyst are 0.001 to 1.2N HC1 and an acetic acid solution.

The present invention also includes within its scope an anti-fogging coating composition comprising the organic-inorganic hybrid composite, an organic compound having unsaturated hydrocarbon groups and one or more hydrophilic groups, a photo-curing initiator and an organic solvent.

The anti-fogging coating composition of the present invention comprises the organic-inorganic hybrid composite in an amount ranging from 2 to 20% by weight, preferably from 5 to 15% by weight based on the total weight of the composition. When the amount is less than 2% by weight, it is difficult to obtain the expected effects of the inventive hybrid composite, and when more than 20% by weight, the viscosity of the coating composition becomes excessively high.

The inventive coating composition further comprises a photo-curable unsaturated organic compound having one or more hydrophilic groups such as ether and hydroxy moieties in the form of a monomer, oligomer or polymer, which serves to increase the compatibility and anti-fogging property of the hybrid composite, in an amount ranging from 10 to 70% by weight, preferably from 20 to 40% by weight based on the total weight of the composition. When the amount is less than 10% by weight, the viscosity of the coating composition becomes excessively high, and when more than 70% by weight, the surface hardness as well as the durability of the anti-fogging property of the coating layer become poor.

Representative examples of the organic compound include 2-hydroxyethyl methacrylate (HEMA), 2-hydroxypropyl methacrylate (HPMA), 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HP A), polypropyleneglycol 5 methacrylate, polyethyleneglycol 6 methacrylate, polypropyleneglycol 6 acrylate, polyethyleneglycol 6 acrylate, polyalkyleneglycol methacrylate, ammonium sulphatoethyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, polyethyleneglycol 200 diacrylate, triethyleneglycol diacrylate, tripropyleneglycol diacrylate, polyethyleneglycol 400 diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, pentaerythritol triacrylate, 3mole added ethoxylated trimethylolpropane triacrylate, 3mole added propoxylated trimethylolpropane triacrylate, 6mole added ethoxylated trimethylolpropane triacrylate, 6mole added propoxylated trimethylolpropane triacrylate, 9mole added ethoxylated trimethylolpropane triacrylate, 15mole added ethoxylated trimethylolpropane triacrylate and ethoxylated pentaerythritol tetraacrylate.

Among the above-mentioned organic compounds, preferably used in the present invention are HEMA, polyethyleneglycol 6 methacrylate, polyethyleneglycol 6 acrylate, polyethyleneglycol 200 diacrylate, triethyleneglycol diacrylate, polyethyleneglycol 400 diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, pentaerythritol triacrylate, 3mole added propoxylated trimethylolpropane triacrylate, 6mole added ethoxylated trimethylolpropane triacrylate, 6mole added propoxylated trimethylolpropane triacrylate, 9mole added ethoxylated trimethylolpropane triacrylate and 15mole added ethoxylated trimethylolpropane triacrylate.

The inventive coating composition comprises a photo-curing initiator, which acts to cross-link unsaturated hydrocarbon groups, in an amount ranging from 1 to 10% by weight based on the total weight of the composition.

Representative examples of commercially available photo-curing initiators are Irgacure 184 (1-hydroxy cyclohexyl phenyl ketone), Irgacure 819

(bis(2,4,β-trimethyl benzoyl)-phenylphosphine oxide), BP (benzophenone), TPO (2,4,6-trimethylbenzoyl-diphenylphosphine), Irganox 1010 (pentaerythritol bis(3-(3,5-di-tert-butyl l)propionate), Irganox 1035 (triodiethylene bis(3-(3,5-di-tert-butyl l)propionate), Irganox 1076 (octadecyl(3-(3,5-di-tert-butyl l)propionate), among which Irgacure 184, Irgacure 819, Irganox 1076 and TPO are preferably used in the present invention.

In order to control the viscosity of the coating composition, the inventive coating composition also comprises an organic solvent in an amount ranging from 0 to 90% by weight, preferably from 30 to 70% by weight based on the total weight of the composition. When the amount is more than 90% by weight, both the surface hardness and anti-fogging property of the coating layer become poor.

The organic solvents suitable for use in the present invention include isopropyl alcohol, diacetone alcohol, n-butanol, toluene, xylene, ethyl cellusolve, butyl cellusolve, methylisobutyl ketone, methylethyl ketone, ethyl acetate and normal butyl acetate, preferably including isopropyl alcohol, n-butanol, toluene, ethyl cellusolve, methylisobutyl ketone, methylethyl ketone and ethyl acetate.

As the inventive coating composition comprises the organic-inorganic hybrid composite containing hydrophilic organic functional groups, photo-curable unsaturated hydrocarbon groups and nano-sized metal oxides for increasing surface hardness, when photo-cured, it provides a transparent anti-fogging coating layer having high adhesion to transparent plastic substrates made of, e.g., polycarbonate, polyacrylate, polyethylene terephthalate and polymethyl methacrylate, high surface hardness and improved, durable anti-fogging property.

The following Examples and Comparative Examples are given for the purpose of illustration only and are not intended to limit the scope of the invention.

Synthesis of organic-inorganic hybrid composites

Preparation Example 1

248 g of methacryloxypropyltrimethoxysilane was dissolved in 200 g of isopropylalcohol at 50 C₅ and a mixed solution of 156 g of

2-hydroxyethylmethacrylate and 2 g of V-60 in 150 g of isopropylalcohol was added thereto at room temperature over a period of 90 min with stirring, and stirred further for 8 hrs to form an acryl polymer.

60 g of 0.0 IN HC1 was added to the above polymer and stirred at 30 ^°C for 30 min. Then, 700 g of IPA-ST (30% SiO₂, diameter: l'0-20nm, Nissan

Chemical) was added thereto over a period of 10 min with stirring, and stirred further for 3 hrs to form a hydrophilic organic material-silicon oxide hybrid.

40g of 0.0 IN HC1 was added to 184 g of methacryloxypropyltrimethoxysilane at 30^°C over a period of 10 min and stirred for 30 min, followed by the addition of the above hybrid over a period of 30 min to obtain a hybrid composite (solid content: 45%).

Preparation Example 2

The procedure of Preparation Example 1 was repeated except that MA-ST (30%) SiO₂, diameter: 10-20nm, Nissan Chemical) was employed instead of IPA-ST, to obtain a hybrid composite.

Preparation Example 3

248 g of methacryloxypropyltrimethoxysilane was dissolved in 200 g of isopropylalcohol at 50 C₅ and a mixture of 211 g of 2-(sulfoxy)ethylmethacrylate ammonium salt and 2 g of V-65 dissolved in 200 g of isopropylalcohol was added thereto at room temperature over a period of 90 min with stirring, and stirred further for 8 hrs to form an acryl polymer.

60 g of 0.01N HC1 was added to the above polymer and stirred at 30 ^°C for 30 min. Then, 700 g of IPA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical) was added thereto over a period of 10 min with stirring, and stirred further for 3 hrs to form a hydrophilic organic material-silicon oxide hybrid.

40 g of 0.01N HC1 was added to 184 g of methacryloxypropyltrimethoxysilane at 30 over a period of 10 min and stirred for 30 min, followed by the addition of the above hybrid over a period of 30 min to obtain a hybrid composite (solid content: 46%).

Preparation Example 4

The procedure of Preparation Example 3 was repeated except that MA-ST (30% SiO , diameter: 10-20nm, Nissan Chemical) was employed instead of IPA-ST, to obtain a hybrid composite.

Preparation Example 5

The procedure of Preparation Example 3 was repeated except that AIBN was employed instead of V-65, to obtain a hybrid composite.

Preparation Example 6

234 g of acryloxypropyltrimethoxysilane was dissolved in 200 g of isopropylalcohol at 50 C ₅ and a mixture of 375 g of poly(ethyleneglycol) acrylate(average M.W.=508) and 3 g of V-65 dissolved in 300 g of isopropylalcohol was added thereto at room temperature over a period of 90 min with stirring, and stirred further for 8 hrs to form an acryl polymer.

60 g of 0.0 IN HC1 was added to the formed polymer and stirred at 30^°C for 30 min. Then, 1000 g of IPA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical) was added thereto over a period of 10 min with stirring, and stirred further for 3 hrs to form a hydrophilic organic material-silicon oxide hybrid.

40 g of 0.0 IN HC1 was added to 174 g of acryloxypropyltrimethoxysilane at 30 C over a period of 10 min and stirred for 30 min, followed by the addition of the above hybrid over a period of 30 min to obtain a hybrid composite (solid content: 45%). Preparation Example 7

The procedure of Preparation Example 6 was repeated except that MA-ST (30%) SiO₂, diameter: 10-20nm, Nissan Chemical) was employed instead of IPA-ST, to obtain a hybrid composite.

Preparation Example 8

The procedure of Preparation Example 6 was repeated except that AIBN was employed instead of V-65, to obtain a hybrid composite. 0

Preparation Example 9

0.001 g of dibutyltindiraurate was dissolved in 200 g of polyethyleneglycol (average M.W.=400), and 121 g of Y -isocyanatopropyltrimethoxysilane was added thereto at 60 C over a period of 30 min with stirring, and stirred further for s 90 min to form a urethane polymer.

50 g of the formed polymer and 100 g of acryloxypropyltrimethoxysilane were mixed at 30^°C₅ and 25 g of 0.00 IN HCl was added to the mixture over a period of 20 min. Then, 100 g of MA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical) was added to the solution over a period of 30 min with stirring, and o stirred further at 40 C for 4 hrs and cooled, to obtain a hybrid composite.

Synthesis of anti-fogging coating compositions Example 1

20 g of hydroxyethyl methacrylate and 0.001 g of 4-methoxyphenol were 5 added to 20 g of the hybrid composite obtained in Preparation Example 1 and stirred at 20 ^°C. 0.5 g of Irgacure 184 and 0.3 g of TPO (photo-curing initiators),

10 g of 9-ethyleneglycol diacrylate oligomer and 40 g of isopropylalcohol were added to the mixed solution and stirred for 1 hr to obtain a coating composition.

0

The procedure of Example 1 was repeated using the hybrid composites obtained in Preparation Examples 2 to 9, to obtain respective coating compositions

5 Example 1 The procedure of Example 1 was repeated except that 50 g of poly(ethyleneglycol) 2,4,6-tris(l-ρhenylethyl)ρhenylether methacrylate was employed instead of 9-ethyleneglycol diacrylate oligomer, to obtain a coating composition.

Example 1 1

The procedure of Example 1 was repeated except that 100 g of methacryloxypropyltrimethoxysilane was employed instead of acryloxypropyltrimethoxysilane, to obtain a coating composition.

Comparative Example 1

Using the conventional method disclosed in Korean Patent 297,952, a coating composition comprising a mixture of hydrophilic organic materials, silica sols and photo-curable silane was prepared as follows; 248 g of methacryloxypropyltrimethoxysilane was dissolved in 200 g of isopropylalcohol at 50 C₅ and a mixture of 156 g of 2-hydroxyethylmethacrylate and 2 g of V-60 dissolved in 150 g of isopropylalcohol was added thereto at room temperature over a period of 90 min with stirring, and stirred further for 8 hrs to form an acryl polymer. Then, 700 g of IPA-ST (30% SiO₂, diameter: 10-20nm, Nissan Chemical) was added thereto over a period of 10 min with stirring, and stirred further for 3 hrs. 184 g of methacryloxypropyltrimethoxy silane was added to the resulting mixture over a period of 30 min to obtain a mixed composite.

20 g of hydroxyethyl methacrylate and 0.001 g of 4-methoxyphenol were added to 20 g of the composite thus obtained and stirred at 20 ^°C . 0.5 g of Irgacure 184 and 0.3 g of TPO (photo-curing initiators), 10 g of 9-ethyleneglycol diacrylate oligomer and 40 g of isopropylalcohol were added to the mixed solution and stirred for 1 hr to obtain a coating composition.

Comparative Example ?.

An anti-fogging coating composition was prepared as described in U.S. Patent Publication No. 2002/0061950A1.

Polymethylmethacrylate having a molecular weight of 150000 and partially hydrolyzed to the extent of 20% was dissolved in a mixed solvent of 1:1 of methanokwater to an amount of 2.3% by weight. 52 g of the resulting solution was added to 47.1 g of 10% polyvinylalcohol (Dp=2000) and stirred at 25 ^°C for 10 min, and then 0.9 g of acetylacetone was added thereto and stirred for 15 min to obtain a coating composition.

Comparative Example 3

The procedure of Example 1 was repeated except that 20 g of polyethyleneglycol (M.W.=400) was employed instead of the organic-inorganic hybrid composite, to obtain a coating composition.

Comparative Example 4

The procedure of Example 1 was repeated except that the organic-inorganic hybrid composite was not used, to obtain a coating composition.

Assay of physical properties Experimental Example 1

The coating compositions obtained in Examples 1 to 11, and Comparative Examples 1, 3 and 4 were each coated on a transparent polycarbonate plate by a flow method, which was subject to drying at 65 ^°C for 5 min to remove the solvent and photo-curing at a rate of lOmpm in UV lamp curing apparatus ('D' type bulb commercially available by Fusion Company) to prepare a respective coating layer.

Experimental Example 2

The coating composition obtained in Comparative Example 2 was coated on a transparent polycarbonate plate by a flow method, which was subject to curing at 100 C for 10 min to prepare a coating layer.

The physical characteristics of the coating layers induced from the coating compositions obtained in Examples 1 to 11 and Comparative Examples 1 to 4 were evaluated in accordance with the following methods.

(1) Adhesion Property : ASTM D3359-87

A coating layer was cut in a checkered pattern at 1mm intervals to form

100 1mm x 1mm squares. An adhesive test tape was firmly attached to the formed pattern and removed at an angle of 180 degrees by a shaφ peeling motion, which was repeated three times. The state of the pattern was examined and the results were evaluated in the following manner:

5B : absence of peeling at the cut edge and williin the pattern area 4B : slight peeling at the cut edge - the area peeled is less than 5% of the pattern area 3B : some peeling and breakage at the cut edge - the area peeled is less than

15% of the pattern area 2B : considerable peeling and breakage at the cut edge and within the pattern area - the area peeled is less than 35% of the pattern area

IB : large ribbon type of peeling - the area peeled is in a range from 35 to

65% of the pattern area OB : poor adhesiveness - the area peeled is more than 65% of the pattern area

(2) Warm Water Resistance : ASTM D3359-87

A coated sample was dipped in distilled water of 100 C for 15 min., pulled out and dried. The state of the coating layer was examined with the naked eye.

(3) Anti-fogging Property

OWarm breath test : a person blew on the surface of a coating layer for 3 seconds, and observed the clearance of the fogged area. "Rating 5" corresponds to the case of no fogging, and "Rating 1", the case that fogging disappears after 10 seconds or more. #Freezer test : a coated sample was kept in a freezer of -20 C for 10 minutes, and exposed to ambient condition to observe fogging. "Rating 5" corresponds to the case that fogging disappears within 30 seconds, and "Rating 1", the case that fogging disappears after 6 minutes or more. • Steam test : a coated sample was brought into contact with water vapor for 2 seconds, and fogging was observed. "Rating 5" corresponds to the case that fogging disappears within 60 seconds, and "Rating 1", the case that fogging disappears after 6 minutes or more. •Cold water test : a coated sample was dipped in cold water of 5 ^°C for 10 seconds, and observed. "Rating 5" corresponds to the case of no fogging, and "Rating 1", the case that fogging disappears after 1 minute or more.

(4) Pencil Hardness : ASTM D3363-74

A coating layer was scratched with a pencil under a constant pressure at an angle of 45 degrees, which was repeated five times. The hardness value of the pencil produced only one scratch or breakage of the coating layer is referred as to pencil hardness.

(5) Weathering resistance

A coating layer placed at a distance of 15cm from a spray nozzle was sprayed with 50 ₅ 80 psi water for 30 min. The state of the sprayed coating was examined with the naked eye to see whether or not peeling occurred, and then the sprayed coating was evaluated as in the warm breath test.

The physical properties of the coating layers thus measured are showed in Table 1. Table 1

Adhesion Warm Anti-fog Pencil Weathering property water ging hardness resistance resistance property Warm State breath

Uncoated 1/1/1/1 2B PC plate

Ex. 5B Good 5/4/5/4 2H No pee ing_

5B Good 5/4/5/5 2~3H No pee mg_

5B Broken 5/5/5/5 No pee mg

5B Broken 5/5/5/5 H No pee^' ιng_

5B Broken 5/5/5/5 2H No pee mg

5B Good 5/5/5/4 2H No pee ιng_

7 5B Good 5/5/5/5 2~3H No pee ιag_

5B Good 5/5/5/5 2H No pee ιng_

5B Turbid 5/5/4/5 H No pee mg.

10 5B Good 5/4/5/4 1~2H No pee ιng_

11 5B Good 5/3/5/4 2H No pee. ng_

Comp. 5B Broken 5/3/5/2 HB .peeling Ex. 0B Separated 5/5/3/2 2B peeling

2B Broken 5/4/4/3 B peeling 3B Turbid 3/1/2/1 B~HB peeling As shown in Table 1, the anti-fogging layers obtained using the inventive compositions show better adhesion, surface hardness and anti-fogging properties than the comparative layers.

As the above results show, the coating composition comprising the hydrophilic organic-inorganic hybrid composite of the present invention can be advantageously used in the preparation of a transparent anti-fogging coating layer having high adhesion to a substrate, high surface hardness and improved, durable anti-fogging property.

While the invention has been described with respect to the specific embodiments, it should be recognized that various modifications and changes may be made by those skilled in the art to the invention which also fall within the scope of the invention as defined by the appended claims.

Claims

WHAT T CT .ATMEP TS-

1. A method of preparing an organic-inorganic hybrid composite which comprises the steps of: (a) reacting a polymerizable hydrophilic organic compound containing one or more terminal hydrophilic groups with a polymerizable alkoxysilane to form a hydrophilic polymer;

(b) reacting the polymer with a nano-sized silica sol to form a hydrophilic nano-sized organic-inorganic hybrid; and o (c) reacting the hybrid with a photo-curable alkoxysilane having one or more terminal unsaturated groups.

2. The method of claim 1, wherein the polymerizable hydrophilic organic compound contains one or more photo-curable unsaturated hydrocarbon groups s and ester groups, and the polymerizable alkoxysilane, one or more unsaturated hydrocarbon groups.

3. The method of claim 1, wherein the polymerizable hydrophilic organic compound contains at least one amino, hydroxy or thiol group, and the 0 polymerizable alkoxysilane, at least one isocyanate group.

4. The method of claim 2, wherein the equivalent ratio of the unsaturated hydrocarbon groups of the hydrophilic organic compound and the alkoxysilane is in the range of 1 : 1 ~ 1.5. 5

5. The method of claim 2, wherein step (a) is conducted at a temperature ranging from 40 to 80 ^°C.

6. The method of claim 2, wherein the polymerizable hydrophilic organic o compound is selected from the group consisting of poly(ethyleneglycol) phenyl ether methacrylate, poly(ethyleneglycol) diacrylate, poly(propyleneglycol) dimethacrylate, poly(propyleneglycol) diacrylate, poly(ethyleneglycol) dimethacrylate, poly(ethyleneglycol) acrylate, poly(ethyleneglycol) methyl ether acrylate, poly(propyleneglycol) acrylate, poly(ethyleneglycol) phenyl ether 5 methacrylate, poly(ethyleneglycol) 2,4,6-tris(l-phenylethyl) phenyl ether methacrylate, 2-hydroxyethylmethacrylate, 2-hydroxypropylacrylate, dipentaerythritol caprolacton hexa acrylate, ethoxylated (9) trimethylol propane triacrylate, ethoxylated (4) pentaerythritol tetraacrylate, ethoxylated (6) trimethylol propane triacrylate, 4-tert-butyl cyclohexyl acrylate, glycidyl vinyl 5 benzyl ether, N,N-diglycidyl aniline, bis(4-glycidyloxyphenyl)methane and 2-(sulfoxy)ethyl methacrylate ammonium salt.

7. The method of claim 2, wherein the polymerizable alkoxysilane used in step (a) is selected from the group consisting of o (3 -acryloxypropy l)methyldimethoxy silane, methacryloxypropyltrimethoxy silane, acryloxypropyltrimethoxysilane, (methacryloxymethyl)phenyldimethylsilane, methacryloxypiOpyltris(trimethylsiloxy)silane and vinyltriethoxysilane.

8. The method of claim 2, wherein a thermal-polymerization initiator is used in s step (a) in an amount ranging from 0.01 to 1% by weight based on the total amount of the reactants.

9. The method of claim 3, wherein the equivalent ratio of the amino, hydroxy or thiol group of the hydrophilic organic compound and the isocyanate group of the o alkoxysilane is in the range of 1 : 1 ~ 1.5.

10. The method of claim 3, wherein the polymerizable hydrophilic organic compound is selected from the group consisting of polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene triol, polyoxytetramethylene glycol, 5 polyethylene adiphate, polypropylene adiphate, polybutylene adiphate, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene diamine and diethylene triamine.

11. The method of claim 3, wherein the polymerizable alkoxysilane is 0 Y -isocyanatopropyltrimethoxy silane.

12. The method of claim 3, wherein a urethane polymerization catalyst is used in step (a) in an amount ranging from 0.001 to 1% by weight based on the total amount of the reactants. 5

13. The method of claim 1, wherein the nano-sized silica sol is used in step (b) in an amount ranging from 15 to 95%) by weight based on the total amount of the reactants.

14. The method of claim 1, wherein the hybrid is employed in step (c) in an amount ranging from 25 to 75% by weight based on the total amount of the reactants.

15. The method of claim 1, wherein the photo-curable alkoxysilane used in step (c) is selected from the group consisting of vinyltrimethoxysilane, acryloxypropyltrimethoxysilane and methacryloxytrimethoxysilane.

16. An organic-inorganic hybrid composite prepared by the method of any one of claims 1 to 15.

17. An anti-fogging coating composition comprising 2~20% by weight of the organic-inorganic hybrid composite of claim 16, 10~70% by weight of a photo-curable organic compound having one or more unsaturated hydrocarbon groups and one or more hydrophilic groups, 1~10% by weight of a photo-curing initiator and 0~90% by weight of an organic solvent.

18. The composition of claim 17, wherein the organic compound is selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, polypropyleneglycol 5 methacrylate, polyethyleneglycol 6 methacrylate, polypropyleneglycol 6 acrylate, polyethyleneglycol 6 acrylate, polyalkyleneglycol methacrylate, ammonium sulphatoethyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, polyethyleneglycol 200 diacrylate, triethyleneglycol diacrylate, tripropyleneglycol diacrylate, polyethyleneglycol 400 diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, pentaerythritol triacrylate, 3mole added ethoxylated trimethylolpropane triacrylate, 3mole added propoxylated trimethylolpropane triacrylate, 6mole added ethoxylated trimethylolpropane triacrylate, 6mole added propoxylated trimethylolpropane triacrylate, 9mole added ethoxylated emtrimylolpropane triacrylate, 15mole added ethoxylated trimethylolpropane triacrylate and ethoxylated pentaerythritol tetraacrylate.