WO2012093871A1

WO2012093871A1 - Mono-fluid type paint composition for coating glass with excellent anti-alkalinity

Info

Publication number: WO2012093871A1
Application number: PCT/KR2012/000124
Authority: WO
Inventors: Dong Soo Kim; Young Seob NO; Ki Chul Nam; Kyu Ho Choi; Peng Sam Park
Original assignee: Akzo Nobel Coatings International B.V.
Priority date: 2011-01-05
Filing date: 2012-01-05
Publication date: 2012-07-12
Also published as: CN103270122A; KR101321864B1; KR20120079721A; CN103270122B

Abstract

The present invention provides a mono fluid type paint composition for coating glass, comprising (a) acrylic resin; (b) block isocyanate resin; (c) silanol resin formed by primarily reacting epoxy based silane and amino based silane at an equivalent ratio of 1~1.5 : 1; (d) an acid catalyst; and (e) a solvent, wherein the silanol resin is comprised in the content of 2 to 10 wt%, based on 100 wt% of the total composition. According to the present invention, excellent adhesion, chemical resistance, UV resistance, and water resistance required as a coating composition, as well we alkali resistance may be secured by using a silanol resin that has more reactive groups and is more physically stable.

Description

MONO-FLUID TYPE PAINT COMPOSITION FOR COATING GLASS WITH

EXCELLENT ANTI- ALKALINITY

FIELD OF THE INVENTION

The present invention relates to a mono-fluid type paint composition for coating glass that exhibits high hardness, excellent adhesion, chemical resistance, water resistance and alkali resistance, and the like, by comprising silanol resin formed by pre- reacting the existing silane based compounds. BACKGROUND OF THE INVENTION

An industrial glass substrate refers to a glass substrate such as a glass panel for a refrigerator or an air conditioner front, a furniture front glass panel, a glass tile for interior, glass for building exterior material, and the like.

A resin composition used for the existing paint composition for coating glass mainly included a polyester based, an epoxy based, or a melamine based resin, but they had inferior properties in terms of adhesion and water resistance. In order to overcome these problems, a silane coupling agent has been added to acrylic resin so as to secure adhesion to glass, which causes a problem of insufficient alkali resistance due to hydrolysis of the ester group included in the acryl group. Particularly, building glass ink is regularly washed with an alkaline detergent, which causes serious deterioration of adhesion due to pollution by the alkaline detergent. Namely, faulty products are generated due to poor adhesion of the paint film resulting from insufficient alkali resistance.

In order to improve alkali resistance, in general, cross-linking degree is increased so that moisture cannot be penetrated into an acryl group that is vulnerable to alkali. A silane coupling agent that does not have a reactive functional group has low adhesion and water resistance because it does not progress a reaction with a main chain. A silane coupling agent having a reactive functional group added for a reaction with a main chain has a storage problem due to a continuous reaction between the functional group and acrylic resin, and thus, it is mainly used as a two-fluid type. Adhesion and water resistance are most important properties of a paint composition for coating glass. Currently, a paint composition for coating glass with improved properties, such as adhesion, water resistance, solvent resistance, chemical resistance, UV resistance, cold resistance and heat resistance, boiling water resistance, alkali resistance, and the like is required, and particularly a mono-fluid type paint composition for coating glass is urgently needed considering paint loss and environmental pollution, and the like.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a mono-fluid type paint composition for coating glass that has reinforced alkali resistance, adhesion, and the like, compared to the existing paint composition for coating glass, and can maintain the initial state for a long period.

The technical objects of the invention are not limited to solving the above- mentioned problems, and other technical objects would be obvious to a person with ordinary knowledge in the art from the following descriptions.

Accordingly, one object of the present invention is to provide a mono-fluid type paint composition for coating glass capable of maintaining the initial state for a long time due to the enhanced properties, such as alkaline resistance, adhesion, and the like, compared to the conventional composition for coating glass.

The objects of the present invention are not limited to solving the above- mentioned problems, which would be clearly appreciated by persons skilled in the art. According to one aspect of the present invention, there is provided a mono fluid type paint composition for coating glass, comprising (a) acrylic resin; (b) block isocyanate resin; (c) silanol resin formed by primarily reacting epoxy based silane and amino based silane at an equivalent ratio of 1-1.5 : 1 ; (d) an acid catalyst; and (e) a solvent, wherein the silanol resin is comprised in the content of 2 to 10 wt%, based on 100 wt% of the total composition. The silanol resin may preferably have a hydro xyl value of 120 to 140, weight average molecular weight of 580 to 680, and solid contents of 80 to 90%.

The acrylic resin may preferably include a hydroxyl group in the molecule, and have an acryl backbone structure.

The acrylic resin may preferably have a glass transition temperature (Tg) of from 20 to 50 ^°C, and weight average molecular weight of 10,000 to 30,000.

The weight ratio of the acrylic resin and the block isocyanate resin may be preferably 5 ~ 9 : 1.

The paint composition for coating glass may preferably comprise (a) 35-80 wt% of the acrylic resin; (b) 8-16 wt% of the block isocyanate reisn; (c) 2-10 wt% of the silanol resin; (d) 0.1-2 wt% of the acid catalyst; and (e) remaining amount of the solvent, based on 100wt% of the total composition.

Preferably, the above explained paint composition for coating glass may further comprise at least one additive selected from the group consisting of an antifoaming agent, a thickener, a curing accelerator, a diluent, a dispersant, a wetting agent, and a surface modifier.

According to another aspect of the invention, provided is a glass product comprising a coating film formed by coating the above explained paint composition for coating glass on one side or both sides of a glass substrate. The glass product may include glass tile for a refrigerator door, a front panel of an air conditioner, and/or building interior and exterior material.

The mono-fluid type paint composition for coating glass of the present invention may improve yellowing and thickening generated by using an amino based silane compound, and exhibit excellent coating film properties such as alkali resistance, weather resistance, high hardness, chemical resistance, adhesion, boiling water resistance, and the like, compared to the existing mono-fluid type paint composition for coating glass.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be explained in detail. Although the existing silane based compounds, such as block isocyanate silane, amino based silane, epoxy based silane, mercaptan based silane, and the like, often exhibit excellent effects in terms of adhesion and water resistance, and the like, there is a lack of alkali resistance. Particularly, the amino based silane may cause discoloration due to yellowing by an amine group at high temperature, and thus, it has been limitedly used as an ingredient of a coating composition. If epoxy silane that does not have reactivity with an acryl main chain is used, improvement in physical properties may not be exhibited when applied to strong alkali, for example, a KOH solution.

The present invention uses silanol resin formed by primary reaction of amino based silane with epoxy based silane, instead of using the existing silane based compound.

In the synthesized silanol resin, a hydrolysis reaction does not occur unlike the existing silane compound, deterioration in basic properties required as a coating composition is not caused. Further, since the silanol resin formed by the primary reaction has more reactive groups in the molecule, structural and physical stability of the final coating film formed by secondary curing reaction of the composition may be secured. Indeed, the present invention may manifest more excellent coating film properties, such as, alkali resistance, high hardness, adhesion, chemical resistance, and the like, compared to the existing paint composition for coating glass, in which a silane based compound is simply added (Comparative Example 5) (See Table 3 below).

The first compositional ingredient of the mono-fluid type paint composition for coating glass of the present invention is silanol resin (c).

The silanol resin of the present invention is formed by primary reaction of silane based compounds to improve alkali resistance. In the synthesis process of the silanol resin, a hydroxyl group is produced, and since the hydroxyl group has reactivity with block isocyanate resin, which may increase degree of crosslinking reaction. Thus, it may prevent moisture penetration into the ester group of acrylic resin lacking alkali resistance, and increase compactness of the coating film through a high temperature curing reaction, thus contributing to the improvement in alkali resistance (Refer to the Reaction Formula 1 below). Meanwhile, if epoxy based silane and amino based silane are simply used together as the ingredients of a coating composition, hydroxyl groups that are generated during synthesis of silanol are not produced, and only the amino based silane reacts with block isocyanate to decrease degree of crosslinking, and thus deteriorating alkali resistance improvement effect.

The silane based reactants forming the silanol resin (c) may include epoxy based silane and amino based silane, and a silanol resin comprised of common silane based compounds known in the art may be used.

[Reaction Formula 1]

Non-limitative examples of the epoxy based silane that can be used in the present invention may include p-(3,4-epoxycyclohexyl)-ethyltrimethoxy silane, γ- glysidoxy propyl methyl diethoxy silane, γ-glysidoxy propyl trimethoxy silane, γ- glysidoxy propyl triethoxy silane, and a combination thereof, which may be included alone or in a combination. Non-limitative examples of the amino based silane that can be used in the present invention may include aminoethyl aminopropyl triethoxy silane, n- phenylaminopropyltrimethoxy silane, trimethoxysilylpropyl diethyl ene triamine, 3-(3- aminophenoxy)propyl trimethoxy silane, amino ethyl amino methyl phenyl trimethoxy silane, 2-aminoethyl-3 -aminopropyl, tris-2-ethyl hexoxysilane, n-aminohexyl aminopropyl trimethoxysilane, trisaminopropyl trismethoxy ethoxy silane, Ν-β- (aminoethyl)-y-aminopropyl trimethoxysilane, N-P-(aminoethyl)-y- aminopropylethoxysilane, N-P-(aminoethyl)-y-aminopropylmethyldimethoxysilane, and a combination thereof, but not limited thereto. They may be used alone or in a combination.

The silnaol resin may be synthesized by mixing the epoxy based silane and the amino based silane in the equivalent ratio of 1 ~ 1.5 : 1, preferably 1— 1.2 : 1 , and reacting them. If the equivalent ratio of the epoxy based silane and the amino based silane is greater than 1.5 : 1, the content of epoxy silane that does not react with block isocyanate may increase, which may increase the content of silane that does not react with block isocyanate, to cause a bad influence on alkali resistance.

The content of the silanol resin may be 2 to 10 wt%, preferably 2 to 5 wt%, based on 100 wt% of the mono-fluid type paint composition for coating glass of the present invention. If the content of the silanol does not fall within the above range, adhesion of the coating film may be decreased, and it may be difficult to expect improvement effect of coating film properties.

The second compositional ingredient of the mono-fluid type paint composition for coating glass of the present invention is acrylic resin (a).

The acrylic resin may increase surface hardness of the coating film and provide adhesion.

The acrylic resin of the present invention is not specifically limited as long as it is a polymer having an acryl group in the molecule, and it may be formed by polymerizing an acryl based monomer or other monomers. Preferably, it has an acryl backbone structure including a hydroxyl group in the molecule.

The acrylic resin may be formed by polymerizing methylacrylate, ethylacrylate, propylacrylate, isopropylacrylate, butylacrylate, n-butylacrylate, isobutylacrylate, n- amylacrylate, isoamylacrylate, n-hexylacrylate, ethylhexylacrylate, 2- hydroxymethylacrylate, hydroxyethylacrylate, hydroxypropylacrylate, laurylacrylate, methylmethacrylate, ethylmethacrylate, propylmethacrylate, isopropylmethacrylate, n- butylmethacrylate, isobutylmethacrylate, n-amylmethacrylate, isoamylmethacrylate, n- hexylmethacrylate, 2-ethylhexylmethacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylate, laurylmethacrylate, acrylic acid, methacrylic acid, styrene monomers or a mixture thereof, and they may used alone or in a combination of two or more kinds. Preferably, methacrylate, butylacrylate, ethylacrylate, 2-hydroxy methacrylate, normal butyl methacrylate, ethylhexylacrylate, methacrylic acid, styrene monomer or a mixture thereof may be used.

The acrylic resin of the present invention may have a glass transition temperature (Tg) of from 20 to 50 ^°C , but not limited thereto. The acrylic resin may have the viscosity of 10000 to 30000 cps, preferably 15000 to 20000 cps considering workability. The acrylic resin may have the weight average molecular weight (Mw) of 10,000 to 30,000, preferably 15,000 to 20,000.

The content of the acrylic resin is not specifically limited, but it may be 35 to 80 wt%, preferably 50 to 80 wt%, based on 100 wt% of the mono-fluid type paint composition for coating glass. If the acrylic resin content is within the above range, good coating film properties and excellent surface hardness and scratch resistance may be exhibited. <Block isocyanate resin>

The third compositional ingredient of the mono-fluid type paint composition for coating glass of the present invention is block isocyanate (b).

Non-limitative examples of the block isocyanate resin that can be used in the present invention may include hexamethylenediisocyanate, toluenediisocyanate, isophorondiisocyanate, 4,4-diphenylmethanediisocyanate, cyclohexylmethanediisocyanate, p-phenylenediisocyanate, blocked with dimethylpyrazole, dimethylmalonate, methylethylketoxime, caprolactam, and the like, or a mixture thereof, and they may be used alone or in a combination of two or more kinds. Preferably, hexamethylenediisocyanate based block isocyanate resin, for example, TC-423B (T&L Co. Ltd.) may be used.

The block isocyanate resin is non-yellowing type multifunctional block isocyanate that may be dissociated, and it has excellent reactivity with a compound having an active hydrogen group and excellent compatibility with an organic solvent. The viscosity of the block isocyanate is not specifically limited, but it may be 4,000 ~ 8,000 cps, preferably 5,000 ~ 7,000 cps, more preferably 6,000 ~ 6,500 cps. The blocked NCO content may be 10 to 20 % of the solution, preferably 14 to 16%.

The content of the block isocyanate resin is not specifically limited, but it may be 8 to 16 wt%, preferably 9 to 13 wt%, based on 100 wt% of the mono-fluid type coating composition for glass. If the content of the block isocyanate resin does not fall within the above range, general coating film properties may be deteriorated due to lack of chemical bonds, and the coating film may be damaged, thus the price competitiveness may be decreased.

The weight ratio of the acrylic resin and the block isocyanate resin may be 5 ~ 9 : 1, preferably 5 - 7 : 1.

The fourth compositional ingredient of the mono-fluid type paint composition for coating glass of the present invention is an acid catalyst (d).

Since the acid catalyst is mixed with other raw materials when coating on a substrate, such as, glass and influences on the viscosity, it may increase viscosity to improve coatability. And, it may influence on the hardness of the coating film.

Non-limitative examples of the acid catalyst may include organic acid, inorganic acid, acid salt, and the like, and they may be used alone or in a combination of two or more kinds. Preferably, strong acid aromatic block sulfonic acid may be used.

As the block agent of the block acid catalyst, amine is generally used. If an amine block acid catalyst is applied for a paint composition for coating glass as in the present invention, amine reacts to have a bad influence on storage performance, generating thickening and gelling, and thus, it may be preferable to use an acid catalyst blocked with epoxy or urethane based polymer.

Hardness of the coating film may be appropriately controlled according to the content of the acid catalyst, and for example, the content may be 0.1-2 wt%, preferably 0.1 to 1 wt%, based on 100wt% of the total mono-fluid type paint composition for coating glass. <Solvent>

The fifth compositional ingredient of the mono-fluid type paint composition for coating glass of the present invention is a solvent (e).

The solvent may include commonly known aqueous solvents and organic solvents without limitations, and the organic solvent may include aromatic, aliphatic, cycloaliphatic hydrocarbon solvent, and the like.

Non-limitative examples of the solvent that can be used in the present invention may include toluene, xylene, ketone such as methylethyl ketone, methylpropyl ketone, methylbutyl ketone, ethylpropyl ketone, methylisobutyl ketone, methylamyl ketone, and the like; ester such as methylacetate, ethylacetate, normalpropylacetate, isopropylacetate, butylacetate, methylcellosolve acetate, cellosolve acetate, butylcellosolve acetate, carbitol acetate, methoxypropyl acetate, and the like; alcohol such as normal propanol, isopropanol, normalbutanol, isobutanol, tertiary butanol, and the like; ether, glycol, and a mixture thereof. If necessary, a low boiling point solvent and a high boiling point solvent may be mixed.

The content of the organic solvent is not specifically limited, and it may be remaining content for satisfying 100 wt% of the mono-fluid type paint composition for coating glass. Preferably, it may be 5 to 30 wt%, based on 100 wt% of the mono-fluid type paint composition for coating glass. <Mono-fluid type paint composition for coating glass> The mono-fluid type paint composition for coating glass may be obtained by uniformly mixing the acrylic resin, block isocyanate resin, silanol resin, acid catalyst and solvent, and if necessary, further introducing an antifoaming agent, a thickener, a curing accelerator, a diluent, or other additives.

According to one preferred example, the composition may comprise 35-80 wt% of the acrylic resin; 8~16 wt% of the hexamethylene diisocyanate based block isocyanate resin; 2—10 wt% of the silanol resin; 0.1-2 wt% of an aromatic block sulfonic acid as the acid catalyst; 5-30 wt% of the solvent, and, as additives, 0.2-2 wt% of an antifoaming agent and 0.1-2 wt% of a thickener. The composition having the above-mentioned composition may have good coating film properties such as excellent adhesion, chemical resistance, UV resistance, water resistance, alkali resistance, and the like.

The mono-fluid type paint composition for coating glass of the present invention, if necessary, may further comprise commonly known additives.

The additive is not specifically limited as long as it is commonly used in a coating composition, and the examples may include an antifoaming agent, a thickener, a curing accelerator, a polymerization initiator, a diluent, a dispersant, a wetting agent, a surface modifier, a curing accelerator, a drying agent, a leveling agent, a plasticizer, a crosslinking agent, a surface drying retarding agent, a pH controlling agent, a flowability controlling agent, a co-solvent, an antiseptic, or other additives.

The content of the additives may be appropriately controlled within a common range according to the use purpose, and it is not limited to a small amount.

The antifoaming agent may include an acryl based, a silicon based antifoaming agent, and the leveling agent may include polysiloxane based additives of BYK347 (BYK company), and the like. The examples of the wetting agent may include modified siloxane, non-ionic alkoxylate, and the like. The examples of the flowability controlling agent may include ethylene glycol, propylene glycol, and the like.

Non-limitative examples of the curing accelerator that can be used in the present invention may include triphenylphosphine, phosphonium borate, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, 2- ethylhexanoic acid salt of DBU, a metal salt such as zinc octylic acid, tin octylic acid, and the like, an urea compound such as phenyldimethylurea, toluenebisdimethylurea, and the like, titanium chloride, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and a mixture thereof.

The diluent may include an organic solvent of toluene, xylene, alkylbenzenecyclohexanone, cyclohexane, methylisobutylketone, methylcellosolve acetate, ethylcellosolve acetate, butylcellosolve acetate, butylacetate, 3-methyl-l- propanol, or a mixture thereof.

According to the present invention, a coating film may be manufactured with the above explained mono-fluid type paint composition for coating glass by using a commonly known method in the field. For example, the paint composition for coating glass of the present invention is coated on a glass substrate, which is then cured and dried to form a coating film.

The substrate on which the coating film is to be formed is not specifically limited as long as it is made of glass material, and the ingredient, shape, and the like are not specifically limited as long as the coating film may be formed thereon. In addition to the above material, a non-metal substrate may be used. Preferably, it may include glass tile for a refrigerator door, a front panel for air conditioner, and/or building interior and exterior material. _„

Before the coating film is formed, the substrate may pass a pre-treatment. The pre-treatment may be conducted according to a commonly known method in the field, without specific limitations. For example, the pre-treatment may be conducted by removing foreign substances, bends, and grooves from the surface of the substrate using a solvent, ultrasonic wave, high pressure air, and the like, and cleaning.

The above explained mono-fluid type paint composition for coating glass may be applied on a substrate by a common coating method such as spray, printing, immersion, coating, and the like.

The coating film formed using the above paint composition for coating glass may have good product properties required as a coating film, as well as alkali resistance (Refer to the following Table 3). Moreover, since the composition may be stored and used in a mono-fluid type, it is convenient compared to the existing two-fluid type paint composition for coating glass, and enables low temperature drying/curing, thus making the process convenient.

The present invention provides a glass product comprising a coating film formed by coating the paint composition for coating glass on one side or both sides of a glass substrate. The product may preferably include household appliances, automobiles, mobile phones, building interior and exterior materials, and the like.

Hereinafter, the present invention will be explained with reference to Examples in detail, but the following Examples and Experimental Examples are only to illustrate one example of the invention, and the scope of the invention is not limited thereto.

Preparation Example 1. Synthesis of acrylic resin (1)

Into a 4-necked flask equipped with a thermometer and a cooling device, 15 wt% of xylene and 25 wt% of dibasic ester were introduced, and the temperature of the mixture was raised to 135 ^°C . 59 wt% of acryl monomers consisting of me hylmethacrylate, normalbutylmethacrylate, 2-hydroxy methylmethacrylate and acrylic acid and 1 wt% of an initiator of tertiary-butylperoxy-benzoate were dripped for 3 hours, and then, the reaction mixture was maintained for 3 hours to synthesize acrylic resin (1). The synthesized acrylic resin had a solid content of 60%, acid value of 7 or less, hydroxyl value of 33, glass transition temperature (Tg) of 50 ^°C , and viscosity of 15,000~20,000cps.

Preparation Example 2. Synthesis of acrylic resin (2)

Acrylic resin (2) was synthesized by the same method as Preparation Example 1 , except using normal ethylacrylate instead of normal butymethacrylate in the acryl monomer composition of the Preparation Example 1. The synthesized acrylic resin had a solid content of 60%, acid value of 7 or less, hydroxyl value of 33, glass transition temperature (Tg) of 20 ^°C , and viscosity of 12,000-15,000cps.

Preparation Example 3. Synthesis of acrylic resin (3)

Acrylic resin (3) was synthesized by the same method as Preparation Example 1, except using normal butylacrylate instead of normal butymethacrylate in the acryl monomer composition of the Preparation Example 1. The synthesized acrylic resin had a solid content of 60%, acid value of 7 or less, hydroxyl value of 33, glass transition temperature (Tg) of -5 ^°C , and viscosity of 10,000-12, OOOcps.

Preparation Example 4. Synthesis of silanol resin

Into a 4-necked flask equipped with a thermometer and a cooling device, 17.5 wt% of isobutanol, 60 wt% of 3-glycidylpropyltrimethoxysilane, and 22.5 wt% of aminopropyltriethxoysilane were introduced, and the temperature of the mixture was raised to 100^°C . The reaction mixture was maintained for 2 hours, and then, cooled to synthesize silanol resin. The synthesized silanol resin had a solid content of 84%, hydroxyl value of 140, and viscosity of 20-25 cps.

[Examples 1-3] Preparation of a paint composition for coating glass

The acrylic resin and silanol resin prepared in Preparation Examples 1 to 4 were respectively mixed with a compositional ratio described in the following Tale 1 to prepare a composition for coating glass.

[Comparative Examples 1-5] Preparation of a paint composition for coating glass

The acrylic resin and silanol resin prepared in Preparation Examples 1 to 4 were respectively mixed with a compositional ratio described in the following Tale 1 to prepare a composition for coating glass. As the ingredient of the paint composition of Comparative Example 5, epoxy based silane and amino based silane were simply used together.

[Table 1]

Exam Exam Exam Compar Compar Compar Compar Compar pie 1 pie 2 pie 3 ative ative ative ative ative

Exampl Exampl Exampl Exampl Exampl e 1 e 2 e 3 e 4 e 5

Acrylic - resin(l) 75 - - 75 - - 75 (Prepar

ation

Exampl

e l)

Acrylic

resin(2) - 75 - - 75 - - (Prepar

ation

Exampl

e 2)

Acrylic 75 resin(3) - - 75 - - 75 - (Prepar

ation

Exampl

e 3)

Block 10 isocyan 10 10 10 10 10 10 10

ate

Silanol

resin 5 5 5 - - - -

(Prepar

ation

Exampl

e 4)

Epoxy 5 5 5. 2.5 based

silane

Amino - - - - - - 5 2.5 based silane

Acid 0.5 0.5 0.5 0.5 ^' 0.5 0.5 0.5 0.5 catalyst

Solvent 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5

Additiv 2 2 2 2 2 2 2 2 es

Total 100 100 100 100 100 100 100 100

Representative examples of the ingredients used in the above composition are as follows.

*block isocyanate: hexamethylenediisocyanate (TC-423B)

* epoxy based silane: 3-glycidyl propyltrimethoxy silane

* amino based silane: 3-aminopropyltriethoxy silane

*solvent: xylene, dibasicester

*acid catalyst: NACURE-N4575

* additives: including antifoaming agent, thickner

Experimental Example 1. Results of property test

The mono-fluid type paint composition for coating glass prepared in Examples 1-3 and Comparative Examples 1~5 were respectively three color printed on a glass substrate to be applied to a thickness of 25~30μιη by a silk screen method, and then, dried, cured, and the properties were evaluated. Reliability test was conducted for each prepared coating film as described in the following Table 2, and the results are described in the following Table 3.

[Table 2]

Test items Test method Acceptance standard

1 Drying condition 180^°C x lOmin

2 Printing substrate GLASS

3 Printing method Using a semi-automatic printer (A4 size), 100 mesh

Water resistance 25 ^°C x 24hrs immersion No bubble, whitening, discoloration faulty

Adhesion 11 lines are drawn with 1 x 1mm No delamination, intervals, attached with Nichiban peeling Tape, and then, rapidly detached.

Boiling resistance 98±^°C x 1 hr immersion. After being No delamination, allowed to stand at room temperature peeling

for 30 minutes, no Blister and

discoloration.

Nichiban Tape adhesion is

confirmed.

MEK Rubbing MEK, 1kg load, until exposed No delamination, peeling

Alkali resistance A sample is immersed in 3% KOH Discoloration, gloss bath drop for 96 hours (4 days), and faulty, delamination then, defects are confirmed.

The samples were agitated every 24 No swelling, and the hours during test, and the KOH like solution was replaced with new one

on 48 hours after testing.

Low temperature -20 ^°C x 72hr No discoloration, resistance spots, and the like

No delamination, peeling, and the like

Pencil hardness Lines are drawn at 5 points with 1kg No discoloration, load, using Mitsubishi-Uni Pencil HB spots, and the like

No delamination, peeling 17 QUV Foil is covered on 1.2 of the total No delamination,

area of the sample in QUV curing peeling

device, and then, allowed to stand for

48 hours.

As the results of experiments, the paint compositions for coating glass comprising silanol resin according to Examples 1 to 3 exhibited excellent properties in terms of adhesion and alkali resistance. Particularly, according to the alkali resistance test progressed in a 3% KOH solution for 96 hours, in Comparative Examples 1 to 5, the KOH solution was permeated into the end portion of the glass printing side within 12 hours to generate complete delamination, while in the paint composition for coating glass comprising silanol resin of the present invention, no fine delamination was generated.

Consequently, it is confirmed that the paint composition for coating glass comprising silanol resin according to the present invention exhibits more excellent properties, compared to the compositions of Comparative Examples 1-4, respectively, simply using either epoxy based silane or amino based silane, as well as to the composition of Comparative Example 5 that uses both epoxy based silane and amino based silane (Refer to Table 3).

[Table 3]

Test items Exampl Exampl Exampl Compar Compar Compar Compar Compar e 1 e 2 e 3 ative ative ative ative ative

Exampl Exampl Exampl Exampl Exampl e 1 e 2 e 3 e 4 e 5

1 Water OK OK OK OK OK OK OK OK resista

nee

2 Adhes 100/10 100/10 100/10 100/10 100/10 100/10 100/10 100/100 ion 0 0 0 0 0 0 0

3 Boilin 100/10 100/10 100/10 NG NG 100/10 100/10 100/100 g 0 0 0 0 0

resista

nee

MEK 500 500 500 500 500 500 500 500

Rubbi times times times times times times times times or ng or more or more or more or more or more or more or more more

Alkali OK OK OK NG NG NG NG NG resista

nee

Low OK OK OK NG OK OK OK OK tempe

rature

resista

nee

Pencil 4H 3H H 4H 3H H 4H 3H hardn

ess

QUV OK OK OK OK OK OK NG OK

Comparative Example 4, yellowing and thickening were generated when preparing ink.

Claims

WHAT IS CLAIMED IS:

1. A mono fluid type paint composition for coating glass, comprising (a) acrylic resin;

(b) block isocyanate resin;

(c) silanol resin formed by primarily reacting epoxy based silane and amino based silane at an equivalent ratio of 1~1.5 : 1 ;

(d) an acid catalyst; and

(e) a solvent,

wherein the silanol resin is comprised in the content of 2 to 10 wt%, based on

, 100 wt% of the total composition.

2. The mono fluid type paint composition for coating glass according to claim 1, wherein the silanol resin has hydroxyl value of 120 to 140, weight average molecular weight of 580 to 680, and solid content of 80 to 90%.

3. The mono fluid type paint composition for coating glass according to claim 1, wherein the epoxy based silane is selected from the group consisting of β-(3,4- epoxycyclohexyl)-ethyltrimethoxy silane, γ-glysidoxy propyl methyl diethoxy silane, γ- glysidoxy propyl trimethoxy silane, γ-glysidoxy propyl triethoxy silane, and a combination thereof.

4. The mono fluid type paint composition for coating glass according to claim 1, wherein the amino based silane is selected from the group consisting of aminoethyl aminopropyl triethoxy silane, n-phenylaminopropyltrimethoxy silane, trimethoxysilylpropyl di ethylene triamine, 3-(3-aminophenoxy)propyl trimethoxy silane, amino ethyl amino methyl phenyl trimethoxy silane, 2-aminoethyl-3 -aminopropyl, tris- 2-ethyl hexoxysilane, n-aminohexyl aminopropyl trimethoxysilane, trisaminopropyl trismethoxy ethoxy silane, N-P-(aminoethyl)-y-aminopropyl trimethoxysilane, Ν-β- (aminoethyl)-y-aminopropylethoxysilane, N- -(aminoethyl)-y- aminopropylmethyldimethoxysilane, and a combination thereof.

5. The mono fluid type paint composition for coating glass according to claim 1, wherein the acrylic resin includes a hydroxyl group in the molecule, and has an acryl backbone structure.

6. The mono fluid type paint composition for coating glass according to claim 1, wherein the acrylic resin has a glass transition temperature (Tg) of from 20 to 50^°C , and weight average molecular weight of 10,000 to 30,000.

7. The mono fluid type paint composition for coating glass according to claim 1, wherein the block isocyanate resin is hexamethylenediisocyanate based block isocyanate resin.

8. The mono fluid type paint composition for coating glass according to claim 1, wherein the weight ratio of the acrylic resin and the block isocyanate resin is 5 ~ 9 : 1.

9. The mono fluid type paint composition for coating glass according to claim 1, wherein the acid catalyst is aromatic block sulfonic acid.

10. The mono fluid type paint composition for coating glass according to claim 1 , comprising

(a) 35-80 wt% of the acrylic resin;

(b) 8-16 wt% of the block isocyanate reisn;

(c) 2-10 wt% of the silanol resin;

(d) 0.1-2 wt% of the acid catalyst; and

(e) remaining amount of the solvent,

based on 100wt% of the total composition.

1 1. The mono fluid type paint composition for coating glass according to claim 1, further comprising at least one additive selected from the group consisting of an antifoaming agent, a thickener, a curing accelerator, a diluent, a dispersant, a wetting agent, and a surface modifier.

12. A glass product comprising

(i) a glass substrate; and

(ii) a coating film formed by coating the paint composition for coating glass of anyone of claims 1 to 1 1 on one side or both sides of the substrate.