WO2024246934A1

WO2024246934A1 - A shatter-proof coating composition

Info

Publication number: WO2024246934A1
Application number: PCT/IN2024/050510
Authority: WO
Inventors: Jagdis S; Sivakumar SAMAYAM; Leila DUMOTIER; Kamel CHAHBOUNE
Original assignee: Saint-Gobain Glass France
Priority date: 2023-05-31
Filing date: 2024-05-10
Publication date: 2024-12-05

Abstract

A shatter-proof coating composition for glass comprising 15 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride, 15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of Octyl salicylate mixture, and 50 to 70 wt% of Ortho-xylene is disclosed. The shatter-proof coating is transparent with visible light transmission of greater than 90%.

Description

A SHATTER-PROOF COATING COMPOSITION

TECHNICAL FIELD

The present disclosure relates, in general to a coating composition, and more specifically to a transparent shatter-proof coating composition for a glass and a method of obtaining a fragmentation retention glass substrate thereof.

BACKGROUND

The past few years have seen several highly publicized incidents involving window and balcony glass breaking spontaneously and falling from high-rise buildings. While such episodes are rare, the danger they pose has forced building code writers, architects, government officials, and related industry professionals to reconsider which types of glass should be specified for glass applications where strength and protection of passers-by are paramount. The term ‘safety glazing’ generally refers to any type of glass engineered to reduce the potential for serious injury when it comes into human contact.

The development of toughened glass must be one of the most significant architectural advancements of the modem age. Used in a vast array of applications, from windows and doors, to furniture, flooring and cookware, automobile glasses used as backlite, sidelites, sunroofs, or windshields etc. In many ways toughened glass has helped revolutionize the way we build and the way we live. Toughened or tempered glass is up to five times stronger than regular plate glass, can withstand surface compression of more than 10,000 psi and is highly resistant to thermal breakage. Nevertheless, they are not indestructible either.

When a tempered glass is broken, it shatters into thousands of tiny pebbles. In many respects these pebbles are far safer than the razor-sharp shards of a regular annealed glass. Therefore, a toughened glass is classified as a safety glass and is specified in areas where safety is a concern. However, in certain circumstances these tiny pebbles can still pose a danger. For example, a glass balustrade, spandrel or overhead glazing that shatters and falls from its frame could cause significant injury to passers-by underneath these structures. Similarly, an automobile windshield, in case of an impact poses threat to human lives.

From time to time, these tempered glasses are known to break, seemingly without any reason, hence rightly termed as spontaneous glass breakage. Ideally the spontaneous glass breakage could be triggered by microscopic internal defects in the glass, minor damages caused during installation, tight binding of the glass in the frame and inadequate glass thickness to resist wind load.

Shatterproof glass is typically made by laminating two or more layers of glass with a layer of plastic in between. While effective, this process can be costly and timeconsuming. Recently, there has been increasing interest in the development of shatterproof glass coatings that can be applied directly to glass surfaces. These coatings are typically made from a variety of materials, including polymers, metals, and ceramics. However, many of these coatings have limitations, such as poor adhesion to glass, low durability, and limited shatter resistance.

It is also known in the art to apply a safety film to the outer surface of a tempered glass substrate to prevent its breakage and thus prevent the shattering or scattering of broken glass pieces in case of glass breakage. Similarly, usage of a laminated glass in place of tempered glass are also prevalent in the market. The interlayer sandwiched between the two layers of glass holds the glass pieces together upon breakage. Use of such laminated glass is mostly associated with windshield glass for automobiles. However, the lamination process can be cumbersome and uneconomical.

Applying an adhesive coating to the surface of glass substrates that allow adherents to be instantly fixed to each other are also not uncommon. One such adhesive coating is disclosed in U.S Publication number 20140004331 that relates to a pressure-sensitive adhesive layer convertible into an adhesive layer that exhibits pressure-sensitive adhesive property before being sintered and adhesive property after being sintered. Referring to German publication number 19906333 discloses single-layer coatings of polymers on display glasses that protect the surface of the glass substrate from the production to the final stage of processing including transportation. The removable coating comprises polyvinyl alcohol and can be removed by washing with organic solvent. Such shatter proofing coatings using PET or vinyl chloride as a raw material are vulnerable to flame or heat and bums when exposed to a high-temperature atmosphere such as one in a fire.

Referring to PCT publication number 2003018701 discloses a self-adhesive protective film for painted surfaces that provides protection to glass, ceramic, VA steel, polycarbonate or acrylic glass during transportation. The self-adhesive protective film comprises a polyolefinic support layer and a self-adhesive layer made of block copolymers comprising butadiene and isoprene and adhesive resins. The above-mentioned coatings or films are associated with difficulties such as pasting of film after cutting the glass into small pieces, bubble formation during film application, delamination, exposed edges prone to edge corrosion, low productivity rate and high production and installation cost. Further, although block copolymers comprising butadiene and isoprene provide high tensile strength and elongation, the adhesion properties of these compounds are significantly low due to their lower surface tension. Furthermore, these compounds exhibit low solubility in solvents and hence require a high solvent content as high as 80% to achieve low viscosity.

There are various types of coatings that can be applied to glass to create shatterproof glass. One type is a polymer coating, which can be applied to the surface of the glass to create a protective layer. However, these coatings can be prone to delamination or degradation over time, which can reduce their effectiveness. Another approach is to apply a coating made from inorganic materials, such as metal oxides or nitrides. These coatings can be more durable than polymer coatings and can provide superior shatter proofing properties. However, they can also be more expensive to produce and apply.

Specifically, when it comes to application of shatter proof coatings in automobile glasses, low-cost safety coatings are typically translucent or opaque in nature and therefore limits their usage where there is a requirement for clarity. Also, their exposure to UV limits their application as it is not resistant to UV.

Notwithstanding all the experience and technology which are available for preventing the shattering or scattering of broken glass pieces in case of glass breakage, it has been discovered that all available solutions are for laminated glasses and the existing solutions do not address reduced weight, cost, optical clarity, UV resistance, transparent and at the same time shatter proofing, that too for a monolithic glass. Thus, there is a need for a shatterproof glass coating composition that overcomes all the above-mentioned disadvantages of available solutions/ compositions in the market for preventing the shattering or scattering of broken glass pieces in case of glass breakage.

More specifically, a shatter proof coating composition which is highly effective, durable, economical, possessing reduced weight, optical clarity and resistant to UV. Such a composition would be of great benefit to a wide range of industries, majorly including automotive and followed by construction industry.

OBJECT OF INVENTION

The main object of the present invention is to provide a transparent shatter proof coating composition for glass, such that the coated glass exhibits a visible light transmission of greater than 90%. Another object of the present invention is to provide a transparent shatter proof coating composition for glass, such that the coated glass is a monolithic glass which is lighter in weight.

Yet another object of the present invention is to provide a transparent shatter proof coating composition for glass, such that the coated glass is resistant to UV.

Further, yet another object of the present invention is to provide a method of obtaining a fragmentation retention glass substrate, such that the glass substrate instantly prevents scattering of broken glass pieces at the time of breakage of the glass substrate.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a shatter-proof coating composition for glass is disclosed. The shatter-proof coating composition comprisesl5 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride, 15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of Octyl salicylate mixture, and 50 to 70 wt% of Ortho-xylene. The shatter-proof coating is transparent with visible light transmission of greater than 90%.

In another aspect of the present disclosure, a method of obtaining a fragmentation retention glass substrate is disclosed. The method comprises the steps of: physical activation of a glass substrate, optionally treating the activated glass substrate with adhesion promoters, providing a layer of the shatter-proof coating composition over the surface of the glass substrate and curing the coated glass substrate below 310 °C.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments are illustrated by way of example and are not limited in the accompanying figures.

FIG. 1 illustrates a glass substrate with a shatter-proof coating, in accordance with one embodiment of the present disclosure.

Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.

DETAILED DESCRIPTION

As used herein, in every embodiment, it must be understood that the term ‘shatterproof coating’ refers to a coating which when applied on a glass substrate prevents scattering of broken glass pieces at the time of breakage of the glass substrate due to any impact or explosion. The shatter-proof coating provided over a glass substrate, further referred herein, has reduced weight, improved optical clarity and UV resistant.

The term ‘glass substrate’ or ‘transparent substrate’, as used herein, interchangeably, refers to a solid-like and transparent material that is used in numerous applications in our daily lives. As referred herein, the substrate is glass which is made from natural and abundant raw materials (sand, soda ash and limestone) that are melted at very high temperature to form a new material. The ‘glass substrate’ referred herein is a single or monolithic glass (unlike a laminated glass), majorly for application in automobiles.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts. Embodiments disclosed herein are related to a shatter-proof coating composition for glass that prevents scattering of glass pieces at the time of breakage of the glass substrate. The present application provides a glass which has shatter-proof property. Referring to FIG. 1 of the present application, which illustrates a fragmentation retention glass 100, in accordance with an embodiment of the present disclosure. The fragmentation retention glass 100 comprises of a glass substrate 110 provided with a shatter-proof coating composition 120 over the surfaces 102 of the glass substrate 110. The shatter-proof coating composition 120 comprises of 15 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride, 15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of Octyl salicylate mixture, and 50 to 70 wt% of Ortho-xylene.

In accordance with the present disclosure the shatter-proof coating 120 provided, ensures that the glass substrate 110 thereof has improved shatter-proof property and specifically, the coating is transparent and has visible light transmission of greater than 90%. Beneficially, the glass substrate 110 provided with the shatterproof coating composition 120 in accordance with the present disclosure is resistant to UV exposure. Further, beneficially, and surprisingly the disclosed glass substrate 110 and the glass 100 thereof not only is highly stable against ultraviolet degradation, but it had also reduced weight as the shatter-proof coating enables the use of a single or monolithic glass substrate, thereby avoiding the use of a laminated glass.

In every embodiment of the present disclosure, the shatter-proof coating composition 120 is provided directly on a monolithic glass substrate 110. The inventors of the present application have realized that in general, PVB material is used to laminate the glasses to get the optical clarity and safety. It is indeed known that optical clarity is achieved from the PVB layer and strength is achieved from the sandwiching of two glasses along with the PVB layer. Without sandwiching PVB layer doesn’t have sufficient adhesion to be stand alone. Glasses used in automotive vehicles are either tempered or laminated. It is also known that laminated glasses are safer than tempered due to their additional strength and retention of broken pieces together at the time of impact or breakage. However, the weight and the cost of laminated glasses is higher compared to tempered glasses. The inventors in accordance with the present disclosure beneficially realized a safety or shatter-proof property being achieved with a single or monolithic glass alone, which thereby reduces the weight as well as cost.

The shatter-proof coating 120 composition in accordance with the present disclosure can be provided on a monolithic tempered and / or annealed glass which would give both retention property during the impact and also makes it safer without adding weight. The shatter-proof coating composition, in accordance with the present disclosure comprises, 15 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride, 15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of Octyl salicylate mixture, and 50 to 70 wt% of Ortho-xylene.

In a preferred embodiment, Styrene Ethylene Butadiene Styrene Maleic anhydride is present in the range of 10 to 20 wt %. In a most preferred embodiment, the Styrene Ethylene Butadiene Styrene Maleic anhydride is present up to 20 wt%. The Styrene Ethylene Butadiene Styrene Maleic anhydride (SEBS-MA) aids in providing shatter-proof property. In some alternate embodiments of the present disclosure, the shatter-proof property can be provided with styrene butadiene styrene (SBS) or styrene isoprene styrene (SIS). In still yet another embodiment, the shatter-proof property can be provided with styrene isoprene butadiene styrene (SIBS).

The hydrogenated tackifiers in accordance with the present disclosure is present in the range of 10 to 30 wt %. In a most preferred embodiment, the hydrogenated tackifiers is present up to 20 wt%. In another aspect of the embodiment, the hydrogenated tackifiers are aliphatic hydrocarbons are C5 aliphatic hydrocarbons having a molecular weight of 830 and cloud point 100 °C. In an alternate embodiment, C5 aliphatic hydrocarbons selected from the group consisting of trans-l,3-pentadiene, cis-l,3-pentadiene, 2-methyl-2-butene, dicyclopentadiene, cyclopentadiene, cyclopentene or their combinations thereof. In still another embodiment, the hydrogenated tackifiers are aromatic hydrocarbons are C9 aromatic hydrocarbons having a molecular weight of 830 and cloud point 100 °C. In an alternate embodiment, C9 aromatic hydrocarbons selected from the group consisting of vinyl toluenes or their isomers, dicyclopentadiene, indene, methyl styrene, styrene, methylindenes or their combinations thereof.

The solvent for the coating composition 120 may be any one of xylene, hexane, heptane, cyclohexane, ethyl benzene, toluene, ketones (unbranched), acetone, esters, glycol esters, ethyl alcohol, butyl alcohol or ethyl hexanol. In a specific embodiment, the solvent is Ortho-xylene. The solvent is preferably present in the range of 40 to 70 wt%. In a most preferred embodiment, the solvent is present up to 60 wt%.

The shatter-proof coating composition, in accordance with the present disclosure comprises Octyl salicylate mixture in the range of 0.5 to 2 wt%. The Octyl salicylate mixture aids in providing resistance against UV. In some alternate embodiments the UV stabilization can also be provided with agents selected from the group consisting of benzophenone-4 and octyl methoxy cinnamate.

The shatter-proof coating composition 120 is made in a reactor by first adding a required amount of solvent in a reflex cleaned reactor. The solvent may optionally be heated for better and faster dissolution. About 15 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride is added to the solvent and mixed until complete or partial dissolution of the SEBS-MA. Following which about 15 to 25 wt % of Hydrogenated tackifiers is added and mixed until complete dissolution. Further after complete dissolution of solid compounds, Octyl salicylate mixture is added. After the addition of this compound the mixing should be prolonged for at least 30 mins to ensure thorough mixing.

The shatter-proof coating composition 120 in accordance with the present disclosure, forms a protective topcoat over the glass substrate 110 and prevents scattering of glass pieces on breakage of the glass substrate 110. The shatter-proof coating composition 120 in accordance with a preferred embodiment of the present disclosure, forms a transparent self-adhesive film on the surface 101 and/or 102 of the glass substrate 110 and the glass pieces formed on breakage of the glass adheres to the film thereby preventing them from scattering. In multiple embodiments, the shatter-proof coating composition 120 has a viscosity ranging between 400 cps and 1600cps with Brookfield viscometer spindle no.28 at ambient temperature. In multiple embodiments, the shatter-proof coating composition 120 has Newtonian rheology with up to 50% solid content. In multiple embodiments, the thickness of the splinter-proof coating composition 120 varies from 30 p and 200 p. In a preferred embodiment, the thickness of the splinter-proof coating composition 120 ranges between 50 p and 100 p.

In a particular embodiment, the SEBS-MA provides increased tensile strength and elongation to the shatter-proof coating composition 120 and makes it viscoelastic. However, when SEBS-MA is used alone in a composition, it cannot be coated at room temperature and requires an increased amount of solvent to achieve Newtonian rheology. The shatter-proof coating composition 120 of the present disclosure has Newtonian rheology with 45% solid content. Whereas the composition with only SEBS-MA has a Newtonian rheology with only 30% solid content.

The hydrogenated tackifiers present in the shatter-proof coating composition 120 of the present disclosure increases the adhesion property of the coating composition 120 and decreases the viscosity thereby enabling the shatter-proof coating composition 120 to be compatible for coating on the surface 101 and/or 102 of the glass substrate 110. In addition, the hydrogenated tackifiers also help in achieving Newtonian rheological behavior and increase the solid content of the shatter-proof coating composition 120. The hydrogenated tackifiers present in the splinter-proof coating composition 120 of the present disclosure aids in increasing surface tackiness and it is compensated by optimizing the SEBS-MA addition. Although the SEBS-MA in the coating composition provides high tensile strength and elongation which is paramount for developing a coating composition that prevents the scattering of glass pieces at the time of breakage of the glass substrate. SEBS-MA does not exhibit UV resistance and good adhesion property owing to its low surface tension. Further SEBS-MA exhibits low solubility in solvents and hence to achieve a low viscosity and Newtonian rheology, solvent levels of up to 40 to 70 % are required. Hydrogenated tackifiers in accordance with the present disclosure when added, reduce the viscosity of the shatter-proof coating composition 120 but however makes the coated surface of the glass substrate sticky thereby rendering a coated glass substrate non-transportable. Finally, when tackifiers in accordance with the present disclosure are added to the composition, these compounds not only reduce the viscosity of the shatter-proof coating composition 120 but also increases the adhesion properties of the shatter-proof coating composition 120 without making the surface of the coated glass substrate sticky.

The addition of UV stabilizers function in various ways in accordance with the present disclosure. Some control the amount of radiation that reaches the polymer, and others inhibit chemical reactions initiated by the absorption of the radiation. The primary methods of UV stabilization involve:

•Absorbing or blocking UV radiation before it can reach the chromophore(s) in the polymer matrix.

•Deactivating or quenching the excited species generated by the UV radiation and converting them into stable, non-reactive forms.

•Scavenging reactive free radicals generated by UV radiation and converting them into stable, non-reactive forms.

Thus, the SEBS-MA, the hydrogenated tackifiers, octyl salicylate mixture and the solvent present in the shatter-proof coating composition 120 of the present disclosure individually contribute for achieving the desired properties of the shatter-proof coating composition 120 of the present disclosure viz., adhesion Class 0-2, 400 cps 1000 cps viscosity with Brookfield viscometer spindle no. 28 at ambient temperature and stickiness and transportability. Thus, the SEBS-MA, the hydrogenated tackifiers, octyl salicylate mixture and the solvent work in synergy to obtain the above-mentioned desired property of the shatter-proof coating composition 120.

In multiple embodiments of the present disclosure, the fragmentation retention glass 100, is used in automotives glass for ex., as backlite, sidelites, sunroofs, or windshields. In every embodiment of the present disclosure, the shatter-proof coating composition has improved adhesion on the glass substrate. The inventors of the present application have optimized the formulation to ensure that adhesion is achieved, without losing the anti-shatter property. SEBS-MA although functions to provide the shatter-proof property, addition of tackifier in an optimum amount as per the present disclosure aid sin improved adhesion and at the same time does not compromise on the shatter-proof property. The inventors of the present application in accordance with the shatter-proof coating composition achieved optimized adhesion of the coating on the glass substrate. If the adhesion is very high then at the time of impact, failure or breakage of monolithic is possible and the glass substrate will not have the retention property. Even if the adhesion is lower, it may create shock absorbance and have retention property however it comprises the durability of the coating. Therefore, the shatter-proof coating composition 120 in accordance with the present disclosure is arrived by the inventors in such a way the adhesion is maintained optimum.

The shatter-proof coating composition 120 provided on the glass substrate, in accordance with the present disclosure additionally exhibits corrosion resistance against chemicals whereby the shatter-proof coating composition 120 that forms the topcoat of the fragmentation retention glass 100. The fragmentation retention glass is resistant to both acidic and alkaline solutions with an exemption to aliphatic hydrocarbon, amyl acetate, amyl alcohol, amyl chloride, aromatic hydrocarbon, benzaldehyde, benzene, benzoic acid, benzyl alcohol, butane, butyl acetate, carbon disulfide, chlorobenzene, chlorobromomethane, chloroform, cyclohexane, cyclohexanone, ethers, gasoline, kerosene, lacquer solvents, linseed oil, methane, naphta, natural gas, nitrobenzene, phenol, phtalic acid, styrene, toluene (toluol), trichloroethylene, turpentine, vinyl plastisol and xylene (xylol). Further the shatterproof coating composition 120 exhibits moisture resistance which in turn prevents corrosion.

The shatter-proof coating composition 120 may be coated using any of the coating techniques selected from the group consisting of spray coating, bar coating, curtain coating, brush coating or other wet coating techniques. Furthermore, the fragmentation retention glass 100, can be subjected to post processing steps including, cutting, transporting, edge grinding and heat treatment at temperatures below 310 °C. The fragmentation retention glass 100, exhibit superior scratch resistance, corrosion resistance, UV resistance, visible light transmission of greater than 90%.

The present disclosure further discloses a method of obtaining a fragmentation retention glass substrate, according to one embodiment of the present disclosure. In multiple embodiments of the present disclosure, the fragmentation retention glass 100 illustrated in FIG. 1 may be obtained by performing all or selected steps of the method in the same or an altered order. The glass substrate is physically activated. In this step the glass substrate is cleaned with DI water and polished with ceria powder in order to remove any surface contamination that may be present on the surface of the glass substrate. In multiple embodiments of the preset disclosure, the glass substrate may be selected from a clear glass.

Further the physically activated glass substrate is treated with adhesion promoters such as silane, organosilane, oligomeric silane, chlorinated and non-chlorinated polyolefin, organotitanates, organozirconates or organoaluminate. In alternate embodiment, this step may be skipped if the coating composition of the present disclosure is to be applied as a temporary coating on the glass substrate. Nevertheless, treating the glass substrate with adhesion promoters improves the adhesion property of the glass substrate and thereby enables better adhesion between the glass substrate and the coating composition of the present disclosure.

Further, the shatter-proof coating composition of the present disclosure is coated on the glass substrate by curtain coating. In alternate embodiments, the shatterproof coating composition may also be coated using other coating techniques such as spray coating, dip coating, wet coating techniques, bar coating and spin coating. The viscosity of the shatter-proof coating composition is selected and optimized according to the coating technique selected for performing this step. The thickness of the shatter-proof coating composition ranges between 50 p and 100 p. In the final step the coated glass substrate is cured at a temperature below 250 °C for a period of 1 to 15 minutes. On curing the splinter-proof coating composition forms a thin transparent film on the surface of the glass substrate.

In optional additional embodiments, the coated glass substrate obtained from performing the disclosed method may be further treated with adhesion promoters listed earlier and provided with a protective topcoat comprising acrylate solutions. This topcoat improves the resistance of the glass substrates against hydrophilic solutions and solvents.

In yet another embodiment of the present disclosure, the curing step involved in obtaining a fragmentation retention lacquered glass substrate may be performed once after subsequent coating of the paint layer and the coating composition layer of the present disclosure in any sequential order.

Examples

Inventive Example 1

Preparation of Shatter-proof Coating Composition A reactor was cleaned by reflex cleaning using a solvent. About 60% of ortho-xylene was added to the reactor. Xylene was heated to a temperature of 40-100 °C to speed-up dissolution rate. About 15 to 25 wt % of SEBS-MA to the overall content of the shatter-proof coating composition was added into the reactor and mixed until complete dissolution of SEBS in xylene. About 15 to 25 wt % of Hydrogenated tackifiers of overall content was added into the reactor until completely dissolved. Then about 0.5 to 1 wt % of Octyl salicylate mixture of overall content was added into the reactor and mixed well.

Comparative Example 1

Using the same method as disclosed in Inventive Example 1, comparative example 1 formulation sis prepared. In this example the formulation consists of SEBS, xylene, C5 aliphatic hydrocarbons and C9 aromatic hydrocarbons.

Comparative Example 2

Using the same method as disclosed in Inventive Example 1, SEBS alone was used.

30 p thick shatter-proof coating composition was coated on a 300x300 mm glass substrate and placed in an oven at 200 °C for about 7 minutes. The coated sample was then removed and cut into 100x25 mm pieces after cooling down the sample to ambient temperature. The sample pieces were then scored in the middle and snapped to the Universal tensile strength equipment without damaging the coating. The rate of loading was maintained at 50 mm/min.

Ball drop test:

Ball drop test was used to determine whether the safety glazing material has a certain minimum strength and cohesion under impact from a small hard object.

Dimensions of the ball:

Ball weight and dimensions:227 g ± 2 g, Ball diameter: 38 mm

Ball drop height: 6 m

It was observed that in the experiments performed for anti-shatter glass in accordance with the inventive example 1, the ball penetrated through the sheet whereas for PVB laminated it doesn’t penetrate. However, the pieces remain intact, unlike tempered glasses. This shows the performance is intermediate between laminated and tempered.

Crosshatch test:

Cross hatch test was mainly used to test the qualitative adhesion of the coating. The coating as per inventive example 1 showed good adhesion with level of 0 to 1.

Adhesion Test:

The adhesion of the coating compositions on glass substrates was measured by cross-hatch (ASTM standard D 3359-00, 6 teeth, 2mm, with brushing and with adhesive tape peel). Pull-off adhesion test is another technique to quantity the adhesion. The inventive example 1 coatings showed adhesion of 4 to 6 MPa.

Light Transmission:

Light transmission values were measured using Haze meter. Typical values for this coating as per inventive example 1 was observed to be between 89 to 91%.

Anti-shatter test:

Test Procedure: Ball peen hammer head to be dropped based on the Mirasafe thickness as mentioned below; While dropping, ball side is the impact side and always down. Weigh of the Ball peen Hammer head - approximately 120g. Qualification: 3 samples to test and all to be passed. In case of single failure, repeat the test for another 3 samples from the same lot and all should pass.

Performance of Anti-shatter test: The samples prepared with the above-mentioned formulation satisfies this test. For all the samples, percentage of retainment is more than 98%.

High Humidity Testing:

The resistance of the samples to high humidity conditions was tested by the Standard EN1036. The samples were exposed to 40°C and >95% relative humidity for a period of 20 days for mirror samples and a period of 21 days for lacquered glass samples. The samples were then tested for appearance of surface corrosion, edge corrosion and further AE* values of the samples were also measured.

Quick Corrosion Test:

Corrosion test was carried out on a 50 x 50 mm sample by immersing the sample in Cupro-hydrochloric salt solution (100 g/L of NaCL, 10 g/L of CuC12. 2H2O and 10 ml of HC1) for 1.5 h at 60oC by placing the paint side facing downwards. The sample was later cut by CNC on the paint side and corrosion levels of these samples were compared with the corrosion level of samples cut manually on the glass side.

Acid Soaking Test:

50 x 50 mm samples were soaked it in H2SO4 for ’A an hour by placing the paint side facing upward the solution and percentage of paint removal was observed visually. Table 1 : Results of Experiments Comparing the Components of the Coating

Composition 120

Table 1 clearly depicts that while the comparable samples fail in most of the 5 experiments the shatter-proof coating composition of the present disclosure clears the specification of all the tests.

INDUSTRIAL APPLICABILITY

With the implementation of the splinter-proof coating composition 120 of the 10 present disclosure, any glass substrates including annealed, tempered, heat strengthened, mirrored and lacquered glass substrates can be converted into a safety glass substrate, wherein the substrates coated with said splinter-proof coating composition prevents scattering of glass pieces at the time of breakage of the glass substrate. Further the splinter-proof coating composition 120 of the 15 present disclosure can be applied as a temporary coating on glass substrates that protects the glass substrates from scratches during transportation. Furthermore, the splinter-proof coating composition 120 offers the coated glass substrates resistance against a wide range of acidic and alkaline solutions and moisture thereby preventing corrosion.

20 With the increasing use of glass substrates for both interior and exterior applications in buildings, safety features associated with such glass substrates becomes critical. The lacquered glass substrates, mirror and clear glass substrates coated with the coating composition of the present disclosure can be readily used for interior applications in a building not limited to wall cladding, curtain walling, furniture’s, flooring, cookware, railing etc. Similarly, these can be used for exterior applications in a building not limited to window glazing, insulated glazing, spandrels, balusters etc.

Note that not all of the activities described above in the general description, or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Certain features, that are for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in a sub combination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.

The description in combination with the figures is provided to assist in understanding the teachings disclosed herein, is provided to assist in describing the teachings, and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a nonexclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

List of Elements Fragmentation Retention Glass Glass Surface Glass Surface Glass Substrate Splinter-proof Coating Composition

Claims

We Claim:

1. A shatter-proof coating composition for glass comprising:

15 to 25 wt % of Styrene Ethylene Butadiene Styrene Maleic anhydride,

15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of Octyl salicylate mixture, and 50 to 70 wt% of Ortho-xylene; characterized in that the shatter-proof coating is transparent with visible light transmission of greater than 90%.

2. The shatter-proof coating composition as claimed in claim 1, wherein the coating can be directly provided on a monolithic glass substrate.

3. The shatter-proof coating composition as claimed in claim 1, wherein the shatter-proof coating composition is resistant to ultraviolet rays and withstands pull off adhesion up to 6 MPa.

4. The shatter-proof coating composition as claimed in claim 1, wherein the hydrogenated tackifiers have a molecular weight of 830 and cloud point 100 °C.

5. The shatter-proof coating composition as claimed in claim 1 has a viscosity ranging between 350 cps and 5000 cps with Brookfield viscometer spindle no. 28 at ambient temperature.

6. The shatter-proof coating composition as claimed in claim 1 when provided on the glass substrate forms a transparent self-adhesive coating.

7. The shatter-proof coating composition as claimed in claim 1, wherein the shatter-proof coating has a thickness ranging between 30 p and 200

8. A method of obtaining a fragmentation retention glass substrate comprising the steps of: physical activation of a glass substrate; optionally treating the activated glass substrate with adhesion promoters; providing a layer of the shatter-proof coating composition as claimed in claim 1 over the surface of the glass substrate; and curing the coated glass substrate below 310 °C to obtain a fragmentation retention glass substrate that instantly prevents scattering of broken glass pieces at the time of breakage of the glass substrate.

9. The method as claimed in claim 8, wherein the glass substrate may be selected from a clear glass or a lacquered glass or a functionally coated glass.

10. A fragmentation retention glass substrate comprising a shatter-proof coating composition as claimed in claim 1 on at least one surface of the non-laminated glass substrate.