An opaque, tack-resistant, and shatterproof glass product and a manufacturing method therefor

Abstract

The present disclosure relates to an opaque, tack-resistant, and shatterproof glass product comprising a glass substrate, either coated or uncoated, and a protective coating based on a thermoplastic polymer composition, applied over the glass substrate. The thermoplastic polymer-based coating contains an opacifier and is designed to provide improved opacity, tack- resistance, and shatterproof properties. Additionally, the present disclosure pertains to a method for manufacturing such a glass product.

Description

[0001] AN OPAQUE, TACK-RESISTANT, AND SHATTERPROOF GLASS PRODUCT AND A MANUFACTURING METHOD THEREFOR TECHNICAL FIELD

[0002] The present disclosure relates, in general, to glass product, specifically to a glass product with opaque, tack-resistant, and shatterproof coatings and a method for manufacturing such a glass product.

[0003] BACKGROUND

[0004] In the glass industry, there is a growing demand for glass products with specific functional properties, such as improved opacity to prevent visibility through the glass, increased resistance to surface stickiness or tackiness, and enhanced shatterproof qualities to reduce the risks of glass breakage. Standard glass coatings may not fully meet these needs, as they often lack sufficient opacity or durability, especially in demanding applications like mirrors or decorative glass surfaces.

[0005] Traditionally, mirrors utilize a protective paint layer over a silvered backing to shield the reflective surface from environmental damage, with the focus mainly on corrosion resistance, adhesion, and durability. However, current shatterproof coatings are typically transparent or optically clear, which fails to address applications requiring opaque mirrors or glass products. In standard glass and mirror applications, opacity is a crucial requirement, particularly for mirrors used in environments where high-backlighting or concentrated light sources are involved. Mirrors in such settings must not only be durable but also sufficiently opaque to ensure light blockage and privacy. On the other hand, shatterproof coatings, while enhancing the mechanical strength and impact resistance of the glass, do not inherently add any significant opacity, limiting their utility in certain design and functional applications.

[0006] Therefore, there is a need to develop a mirror with improved opacity, tack-resistance, and shatterproof properties, ensuring safety and durability. Also, an efficient manufacturing process is required to produce such mirrors cost-effectively.SUMMARY

[0007] This summary is intended to introduce, in simplified form, a selection of concepts that are further described in the detailed description. This summary is merely presented as a brief overview of the subject matter described and claimed herein and does not aid in determining the scope of the claimed subject matter.

[0008] The present disclosure relates to an opaque, tack-resistant, shatterproof glass product and a method for manufacturing such a glass product. The present disclosure provides an opaque, tack-resistant and shatterproof glass product, which is achieved by applying a protective coating over a glass substrate. The protective coating is formulated to impart improved opacity, tack-resistance, and shatterproof characteristics.

[0009] In an aspect, the present disclosure provides an opaque, tack-resistant, shatterproof glass product comprising: a glass substrate, either coated or uncoated, and a protective coating based on a thermoplastic polymer composition, applied over the uncoated or coated glass substrate; wherein the thermoplastic polymer-based coating comprises an opacifier, and is designed to impart improved opacity and tack-resistance along with shatterproof properties.

[0010] In another aspect, the present disclosure provides a method for manufacturing an opaque, tack-resistant and shatterproof glass product. The method comprises the steps of providing a coated or an uncoated glass surface, applying a protective coating based on thermoplastic polymer composition, wherein the protective coating contains an opacifier and imparts improved opacity, tack-resistance and shatterproof properties to the glass product and curing the coating to obtain an opaque, tack-free shatterproof glass product.

[0011] BRIEF DESCRIPTION OF FIGURES

[0012] The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein, like reference numerals represent like elements and in which:FIG. 1 illustrates an opaque, tack-resistant and shatterproof mirror in accordance with an embodiment of the present disclosure.

[0013] FIG. 2 illustrates the corrosion test for an opaque, tack-resistant, and shatterproof mirror in accordance with an embodiment of the present disclosure.

[0014] FIG. 3 illustrates an opaque, tack-resistant, and shatterproof mirror with a bilayer bicoat system in accordance with an embodiment of the present disclosure.

[0015] FIG. 4 illustrates an opaque, tack-resistant, and shatterproof mirror with single-layer bi-coat in accordance with an embodiment of the present disclosure.

[0016] DETAILED DESCRIPTION

[0017] The present disclosure can be understood more readily by reference to the following description, taken in conjunction with the accompanying Figures and Examples, all of which form a part of this disclosure.

[0018] At the very outset of the detailed description, it may be understood that the ensuing description only illustrates a particular form of this invention. However, such a particular form is only an exemplary embodiment, and without intending to imply any limitation on the scope of this invention. Accordingly, the description is to be understood as an exemplary embodiment and teaching of invention and not intended to be taken restrictively.

[0019] Before the present disclosure or methods of the present disclosure are described in greater detail, it is to be understood that the specific products, methods, processes, conditions or parameters, are not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0020] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the methods. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the methods. Certain ranges are presented herein with numerical values being preceded by the term “about.”The term “about” is used herein to provide literal support for the exact number that it precedes, as well as a number that is near to or approximately the number that the term precedes. For example, "about" can mean within one or more standard deviations, or within ± 30%, 25%, 20%, 15%, 10% or 5% of the stated value.

[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. For the purposes of the present invention, the following terms are defined below.

[0022] It is appreciated that certain features of the methods, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the methods, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. All combinations of the embodiments are specifically embraced by the present invention and are disclosed herein just as if each and every combination was individually and explicitly disclosed, to the extent that such combinations embrace operable processes and / or composites / scaffolds .

[0023] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0024] As used herein, the term "comprises", "comprising", or “comprising of’ is generally used in the sense of include, that is to say permitting the presence of one or more features or components. The term "comprises", "comprising", or “comprising of’ when placed before the recitation of steps in a process or method means that the process or method encompasses one or more steps that are additional to those expressly recited, and that the additional one or more steps may be performed before, between, and / or after the recited steps.

[0025] Reference throughout this specification to “certain embodiments”, “further embodiments”, “specific embodiments”, “further specific embodiment”, “one embodiment”, “a non-limiting embodiment”, “an exemplary embodiment”, “some instances”, or “furtherinstances”, means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure.

[0026] As used herein, the terms ‘include’, ‘have’, ‘comprise’, ‘contain’ etc. or any form of said terms such as ‘having’, ‘including’, ‘containing’, ‘comprising’ or ‘comprises’ are inclusive and will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0027] The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illustrate the disclosure and does not pose a limitation on the scope of the disclosure otherwise claimed.

[0028] As used herein, the term “invention”, “present invention”, “disclosure” or “present disclosure” as used herein is a non-limiting term and is not intended to refer to any single embodiment of the particular invention but encompasses all possible embodiments as described in the specification.

[0029] The terms “process(es)” and “method(s)” are considered interchangeable within this disclosure.

[0030] In an embodiment, the present disclosure provides an opaque, tack-resistant, and shatterproof glass product.

[0031] In certain embodiments, the opaque, tack-resistant, and shatterproof glass product comprises:

[0032] a glass substrate, either coated or uncoated, and

[0033] a protective coating based on a thermoplastic polymer composition, applied over the uncoated or coated glass substrate; wherein the thermoplastic polymer-based coating comprises an opacifier, and is designed to impart improved opacity and tack-resistance along with shatterproof properties.In certain embodiments, the coated glass substrate is selected from the group consisting of thin film layers, mirrors, lacquered glass, glass with inorganic coatings, or a combination thereof.

[0034] In certain embodiments, the protective coating is formed from a thermoplastic polymer composition comprising about 10-15 wt % of styrene block copolymer; about 15-20 wt % of a hydrogenated tackifier; about 0.1-1 wt % of an additive; about 50-70 wt% of a first solvent; about 0.1-30 wt % of an opacifier dispersed in a second solvent. In some embodiments, the styrene block copolymer comprises styrene ethylene butadiene styrene (SEBS), SEBS malic anhydride, other SEBS copolymers, styrene-butadiene- styrene (SBS), or styrene-isoprene-styrene (SIS), or a combination thereof. In some embodiments, the styrene content of the styrene block copolymer is about 25-35%. In certain embodiments, the styrene block copolymer comprises SEBS. In certain embodiments, the thermoplastic polymer composition has a viscosity of about 60 seconds as measured by Ford Cup No. 4. In some embodiments, the SEBS has a styrene content of about 25-30 %, which balances elasticity and rigidity to optimize shatterproof properties.

[0035] In certain embodiments, the protective coating is formed from a composition consisting essentially of about 10-15 wt % of SEBS; about 15-20 wt % of a hydrogenated tackifier; about 0.1-1 wt % of an additive; about 50-70 wt% of the first solvent; about 0.1-30 wt % of an opacifier dispersed in the second solvent; wherein the SEBS has a styrene content of about 25-30 %. In some embodiments, the composition has a viscosity of about 60 seconds as measured by Ford Cup No. 4.

[0036] The hydrogenated tackifier may be a petroleum resin that may further be selected from a group comprising an aliphatic C5 petroleum resin, an aromatic C9 petroleum resin, a C5-C9 petroleum resin, or a combination thereof. In some embodiments, hydrogenated tackifier is a combination of an aliphatic C5 petroleum resin, an aromatic C9 petroleum resin. In some instances, hydrogenated tackifier comprises about 8-12 wt% of C5 aliphatic hydrocarbons and about 5-7 wt% of C9 aromatic hydrocarbons. In certain embodiments, the C5 aliphatic hydrocarbons are selected from the group comprising trans- 1,3 -pentadiene, cis-l,3-pentadiene, 2-methyl-2-butene, dicyclopentadiene, cyclopentadiene, cyclopentene, and combinations thereof. In some embodiments, the C9 aromatic hydrocarbons have a molecular weight of about 830 and cloud point of about 100 °C. The C9 aromatic hydrocarbons are selected from thegroup comprising vinyl toluene or their isomers, dicyclopentadiene, indene, methyl styrene, styrene, methylidenes, and combinations thereof.

[0037] In certain embodiments, the protective coating comprises about 0.5-1 wt % of an additive. Organo silanes and / or organo modified polysiloxanes may be used as additives. In some embodiments, the additive is organo modified polysiloxane. Examples include, but are not limited to amino silanes, amino-modified polysiloxanes, epoxy silanes, epoxy-modified polysiloxanes, vinyl silanes, vinyl-modified polysiloxanes, alkyl silanes, alkyl-modified polysiloxanes, phenyl-modified polysiloxanes, Polyether-modified polysiloxanes, and the like.

[0038] In certain embodiments, the glass product is an opaque, tack-resistant, and shatterproof mirror.

[0039] In certain embodiments, the mirror comprises at least one paint layer covering the reflective surface of the mirror substrate. The paint layer may include a single coat, as illustrated in FIG. 1, or either a bilayer bi-coat system or a single-layer bi-coat, as illustrated in FIG. 3 and FIG. 4, respectively. The paints used can be acrylic, alkyd, epoxy, or polyurethane paints. In some embodiments, the paint layer applied over the reflective surface of the mirror substrate is lead-free or substantially lead-free.

[0040] In certain embodiments, the reflective surface of the mirror substrate is a metallic coating comprising silver, aluminum, chromium, or a combination thereof. In some embodiments, the reflective surface comprises silver.

[0041] In certain embodiments, the protective coating comprises at least one opacifier. The opacifier may be selected from a group comprising carbon black, graphite, barium sulphate, titanium dioxide, and a combination thereof. In some embodiments, the opacifier is dispersed in the second solvent. In some instances, about 0.1-30 wt% of the opacifier is dispersed in about 10-15 wt% of the second solvent.

[0042] The first solvent and the second solvent are each independently selected from a group comprising o-xylene (ortho xylene), diacetone alcohol (DAA), isobutyl alcohol (IB A), acetone, and a mixture thereof. In some embodiments, the first solvent is o-xylene. In further embodiments, the second solvent is DAA.In certain embodiments, the opacifier is carbon black. In certain embodiments, the dispersion quality may be optimized by evaluating opacifier such as carbon black in different solvents, including but not limited to, o-xylene, DAA, and IB A. In some embodiments, DAA exhibits superior dispersion stability, attributed to its higher polarity (3.2 vs. Xylene’s 2.5). Thus, in some instances, the opacifier is about 0.1-30 wt% of carbon black dispersed in about 5-50 wt% of DAA. In some embodiments, ultrasonication and dispersing agents may be employed to further improve dispersion quality of the opacifier.

[0043] In certain embodiments, the protective coating has a thickness in the range of about 10 to about 150 microns. This thick range is optimized to ensure a balance between sufficient mechanical strength and opacity while maintaining ease of application. A thickness within this range also contributes to enhanced shatterproof properties and effective coverage of the underlying protective paint layer, thereby improving durability and aesthetic quality of the coated mirror or glass substrate.

[0044] In certain embodiments, the mirror substrate is a glass, quartz glass, sapphire, zerodur and the like. In some embodiments, the mirror substrate is a glass.

[0045] In certain embodiments, a mirror according to the present invention will be described with reference to FIG. 1. The mirror comprises a glass substrate with a silver reflective surface; one paint layer covering the silver reflective surface of the glass substrate; and a protective coating (opaque-shatterproof coating) based on thermoplastic polymer composition, applied over the paint layer; wherein the protective coating comprises an opacifier, and imparts both opacity and shatterproof properties to the mirror. The paint, paint layer, thermoplastic polymer composition, and opacifier are same as defined in the preceding embodiments.

[0046] In certain embodiments, the protective coating of the mirror has an optical density of at least 3, a pull-off adhesion strength of 7.51 MPa when measured according to the Pull-Off Adhesion Method, and / or provides shatter resistance characterized by a minimum impact strength of Y.

[0047] The glass product with opaque, tack-resistant, and shatterproof coatings is particularly valuable in the mirror manufacturing industry. It provides enhanced safety and durability, making it ideal for mirrors used in high-traffic areas, automotive applications, and commercial settings where breakage and surface damage are concerns. The opaque and tack-resistantproperties ensure a long-lasting, easy-to-maintain mirror surface that resists smudges and fingerprints. Additionally, its shatterproof feature significantly improves safety, reducing the risk of injury from broken glass. This product is also suitable for the production of high-quality mirrors for both decorative and functional uses, such as safety mirrors, bathroom mirrors, and mirrors for public spaces, where durability and safety are essential.

[0048] The present disclosure also provides a method for manufacturing an opaque, tackresistant, and shatterproof glass product. In certain embodiments, the method comprises the steps of:

[0049] a) providing a coated or an uncoated glass surface;

[0050] b) applying a protective coating based on thermoplastic polymer composition, wherein the protective coating contains an opacifier and imparts improved opacity, tack-resistance and shatterproof properties to the glass product; and

[0051] d) curing the coating to obtain an opaque, tack-free shatterproof glass product.

[0052] In certain embodiments, the glass substrate, thermoplastic polymer composition, and opacifier are same as defined in the preceding embodiments.

[0053] In a specific embodiment of the present disclosure, the method comprises applying at least one paint layer covering the reflective surface of the mirror substrate. These paints can be applied using various methods known in the art, such as roller application or curtain coating. The paint layer may be applied to the reflective surface of the mirror using a wet process, sputtering, vacuum evaporation, or a combination thereof. In some embodiments, the paint layer applied over the reflective surface of the mirror substrate is lead-free or substantially lead-free.

[0054] In certain embodiments of the method, the coating composition or thermoplastic polymer composition is prepared by dispersing an opacifier in a first solvent to form a uniform dispersion; and adding the uniform dispersion to a suspension or solution comprising a styrene block copolymer, a hydrogenated tackifier, a first solvent, and an additive. The thermoplastic polymer or styrene block copolymer, the hydrogenated tackifier, the fist solvent, and the additive are the same as defined above.

[0055] In certain embodiments, the thermoplastic polymer composition used in the method has a viscosity of about 60 seconds as measured by Ford Cup No. 4. In some embodiments, SEBSis used in the thermoplastic polymer composition, and the SEBS has a styrene content of about 25-30 %.

[0056] In certain embodiments, the method for manufacturing an opaque, tack-resistant, and shatterproof mirror comprises coating the painted side of the mirror substrate with a primer followed by the protective opaque shatterproof coating. In certain embodiments, the primer is applied using a spraying technique and allowed to cure for about 2-3 minutes before the opaque, shatterproof coating is applied using a bar applicator at a wet film thickness of about 250 microns. Other known techniques, such as spray coating, dip coating, wet coating methods, bar coating, and spin coating, may also be employed for the coating process.

[0057] The coated substrate is then cured. In certain embodiments, it is cured at temperature less than about 250°C for about 5-30 minutes.

[0058] In certain embodiments, the method begins with washing the painted side of the mirror substrate using a glass washing machine or manual cleaning to remove contaminants. This is followed by the application of an amino silane primer to promote adhesion between the paint layer and the opaque, shatterproof coating. The primer ensures the integrity and durability of the layered structure, particularly under mechanical stress and environmental conditions. In some embodiments, the primer composition may be enhanced with nano-silica or other silane-based additives to improve bonding between the glass substrate and the coating. This may enable better performance under extreme mechanical or thermal stress.

[0059] In certain embodiments, the method for manufacturing the opaque, tack-resistant, and shatterproof mirror is designed to be compatible with existing mirror production lines without requiring additional capital investment. The process of coating, drying, and curing is performed using the standard equipment available in conventional mirror manufacturing setups, ensuring cost efficiency and ease of implementation.

[0060] The present disclosure is further described with reference to the following examples, which are only illustrative in nature and should not be construed to limit the scope of the present disclosure in any manner.EXAMPLES:

[0061] The Examples describe the development of an opaque, tack-resistant, and shatterproof mirror and a black, shatterproof mirror with a thermoplastic coating. The SEBS-based protective coating was applied on top of the mirror paint layer to provide two properties: opacity and shatter proofness. The development of the composition / formulation, the coating of the developed composition / formulation, and the results of the tests performed are detailed below:

[0062] Comparative Example 1 (CE 1): Shatterproof Coating Composition

[0063] 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 30 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.

[0064] Inventive Example 1 (IE 1): Opaque, Shatterproof Coating Composition / Formulation: Dispersion experiments in different solvents:

[0065] Three solvents were used for dispersion of carbon black, namely, Xylene, Diacetone alcohol (DAA) and Iso Butyl Alcohol (IB A). 50g of carbon black was mixed with 150 g of the chosen solvents to check dispersion and compatibility of the solvent with carbon black. The dispersions are stored in sealed containers at room temperature for 7 days to check for the stability of the dispersion.

[0066]

[0067] Considering that both DAA and IB A have a polarity of 3.2 versus xylene having a polarity of 2.5, the dispersion properties of the former two solvents were observed to be similar compared to the latter.It was also observed that xylene exhibits moderate wetting compared to the other two solvents and needs a longer stirring period or extensive milling in a basket mill to prevent agglomeration. This can also be further enhanced using ultrasonication which in turn adds to the energy utilisation in the formulation step.

[0068] The choice of dispersing agent is critical in achieving optimal dispersion in each solvent. From the above experiment, it may conclude that DAA and IBA are more effective solvents for dispersing carbon black, providing better stability and dispersion compared to xylene. DAA was chosen as a solvent for dispersion of carbon black, which is then added to the shatterproof formulation.

[0069] Preparation: Carbon black was added to a solvent and ensured a uniform dispersion followed by addition to a shatterproof coating composition containing 15 to 25 wt % of styrene ethylene butadiene styrene maleic anhydride, 15 to 25 wt % of Hydrogenated tackifiers, 0.5 to 1 wt % of organo modified poly siloxane, and 50 to 70 wt% of Ortho-xylene. The percentage by weight of carbon black added was varied between 10% to 25% to check the improvement in opacity obtained and results were described.

[0070] The specific formulation used for coating on mirror is shown in Table 1.

[0071] Table 1

[0072]

[0073] 1. Coatins methodology:

[0074] To try the effectiveness of formulation prepared and described above, a simple bar applicator was used to check quality of coating and conduct tests described in sections below. Painted side of a mirror was washed in a glass washing machine (can be manually washed as well). This is followed by a priming step. Priming is done manually by spraying amino silane andwaiting for 2-3 minutes to allow the primer to cure. Post priming, the mirror is ready to be coated.

[0075] The bar is set to 250 microns wet film thickness and placed at the edge of the substrate. A small amount of the formulation is poured in front of the bar. The bar is drawn across the substrate at an even speed and pressure ensuring that coating thickness is uniform across the substrate. The coated sample is then cured at 150°C for 15 minutes to ensure complete curing of the mirror sample (see Table 2).

[0076] Table 2

[0077]

[0078] 2. Trial with different concentrations:

[0079] To optimize the concentration of carbon black utilized in the formulation, the weight percent of carbon black was varied in the SEBS-C5-C9 formulation. Three different concentrations were used and dispersion of carbon black in DAA was recorded. Coating quality was visually checked, and optical density was measured. The results are shown in Table 3.

[0080] Table 3

[0081]

[0082]

[0083] Tests Conducted:

[0084] 3. CASS test for corrosion

[0085] The Copper Accelerated Salt Spray Test (CASS test) is a specialized corrosion test used to evaluate the resistance of materials, particularly metals and coatings, to corrosion in a simulated, accelerated environment. The test accelerates the corrosion process, allowing for quicker assessment compared to real-world environmental exposure. A solution of 5% Nacl + 0.26g / Ltr of CUCI2.2H2O + Acetic acid was prepared to make the solution pH to 3.0 - 3.1). Samples were placed in a controlled chamber where they were exposed to a fine mist of the salt solution. Corrosion levels on the samples were measured before and after every cycle consisting of 5 days. An edge corrosion of up to 1200 microns after the first cycle is considered acceptable as per ASTM Bl 17. The corrosion data (first cycle) for a mirror + protective back paint, mirror + protective back paint + shatterproof coating and mirror + protective back paint + opaque shatterproof coating are shown in FIG. 2. It can be seen that the corrosion values are well below the specification of 1200 microns and the corrosion values for opaque shatterproof coating are on par with mirror with protective paint and mirror with protective paint and regular shatterproof (not high opacity).

[0086] 4. Probe tack test

[0087] The probe tack test is a method used to evaluate the tackiness of adhesive materials in general and has been used as a measure of understanding the tackiness of the coating. When large productions of mirror are done, sheets are stacked against each other. It is desirable that the coating should be non-tacky to ensure that once stacked, the sheets do not stick or adhere to each other, making it challenging to separate them from one another at the time of transport and distribution to customers. Typically, tackiness typically reduces over time due to a combination of chemical, environmental, and mechanical factors and it is therefore important to check tackiness immediately after the sample is coated. A comparison between the mirror coated with the shatterproof coating of IE1 and the mirror coated with the opaque, tackresistant, and shatterproof coating of IE 1 is shown below in Table 4.Table 4

[0088] <

[0089]

[0090] 5. Shatterproof test in comparison with existing shatterproof coatins

[0091] To check the shatter retention property of the coating, the following test was conducted. Initial weight of the sample was measured. The sample was placed in a zip lock cover and placed on the ground. From a pointed hammer head at 0.8m height, a 120g weight is dropped to shatter the sample. The weight of the remaining sample was calculated. If 98% of the original weight of the sample is retained, it indicates that the anti-shatter property exists in the sample.

[0092] The anti-shatter test for the opaque shatterproof samples exhibited a weight retention of 99.9%, repeated over three sets, which complies with the specification of 98%, indicating that the coating helps prevent the shattering of the mirror samples.

[0093] 6. Pull off adhesion test

[0094] A “pull-off adhesion test” was used to measure the adhesion strength of a coating to a substrate. A test area was selected, and the surface was cleaned to remove any contaminants. A loading fixture, often called a dolly, was glued to the coating surface using a strong adhesive. The adhesive was allowed to cure before testing. A pull-off testing device was then attached to the dolly, applying an increasing tensile force perpendicular to the surface until the dolly was pulled off. The force required to detach the dolly was measured. This test provided the force at which the coating failed.

[0095] For the invention described here, the measured force at which the dolly completely detached was observed to be 7.51 MPa, indicating good adhesion of the coating to the protective mirror paint beneath.

[0096] 7. Optical density and comparison with existing productsMirrors coated with the opaque, shatterproof coating (IE 1) exhibited an optical density of 5.51, indicating 0.001% transmission of incident light, hence making them opaque for applications with concentrated backlighting.

[0097] Optical density (OD) measurements are an important aspect in the evaluation of optical properties of coatings. It is a measure of how much light is absorbed by a material and quantifies the extent to which a coating can attenuate the transmission of light through it.

[0098] In general, an optical density of 3 or higher is considered to indicate an opaque coating, meaning it transmits less than 0.1% of the incident light. In the table below, optical density of three samples were measured, namely: Mirror with protective paint coated, Mirror with protective paint along with a translucent shatterproof coating and mirror with protective paint followed by the opaque shatterproof coating described in this invention.

[0099] All three mirror samples exhibited an optical density of greater than 3 indicating sufficient opacity. However, some applications of mirror require the placement of a concentrated light illuminated from the paint side. Mirrors that were coated with only regular paint or regular paint plus a shatterproof coating (CE 1) were found unsuitable for such applications. The results are shown in Table 5.

[0100] Table 5

[0101]

[0102] While preferred embodiment and an example configuration have been shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred nature of the invention and should not be interpreted as limitations on the scope of the invention.The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0103] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

Claims:

1. A gl as s product compri si ng :a) a glass substrate, either coated or uncoated, andb) a protective coating based on a thermoplastic polymer composition, applied over the uncoated or coated glass substrate; wherein the thermoplastic polymer-based coating comprises an opacifier, and is designed to impart improved opacity and tackresistance along with shatterproof properties.

2. The glass product as claimed in claim 1, wherein the coated glass is selected from the group consisting of thin film layers, mirrors, lacquered glass, glass with inorganic coatings, or a combination thereof.

3. The glass product as claimed in claim 1, wherein the glass product is an opaque, tack- free, shatterproof mirror.

4. The glass product as claimed in claim 1, wherein the protective coating is formed from a composition comprising:about 10-15 wt % of styrene block copolymer;about 15-20 wt % of a hydrogenated tackifier;about 0.5-1 wt % of an additive;about 50-70 wt% of a first solvent;about 0.1-30 wt % of an opacifier dispersed in a second solvent.

5. The glass product as claimed in claim 1, where in the protective coating is entirely tack- free.

6. The glass product as claimed in claim 1 or 4, wherein the opacifier is selected from a group comprising carbon black, graphite, barium sulphate, titanium dioxide and a combination thereof; and the styrene block copolymer comprises styrene ethylene butadiene styrene (SEBS), SEBS malic anhydride, other SEBS copolymers, styrene- butadiene-styrene (SBS), or styrene-isoprene-styrene (SIS), or a combination thereof.

7. The glass product as claimed in claim 4, wherein the styrene content of the styrene block copolymer is about 25-35%.

8. The glass product as claimed in claim 4, wherein the hydrogenated tackifier comprises an aliphatic C5 petroleum resin, an aromatic C9 petroleum resin, a C5-C9 petroleum resin comprising from 8-12 wt% of the aliphatic C5 and 5-7 wt% of the aromatic C9 or a combination thereof.

9. The glass product as claimed in claim 4, wherein the first solvent and the second solvent are each independently selected from a group comprising xylene, diacetone alcohol, isobutyl alcohol, acetone, and a mixture thereof.

10. The glass product as claimed in claim 1, wherein the protective coating has a thickness in the range of about 10 to about 150 microns.

11. The glass product as claimed in claim 2, wherein the mirror substrate is a glass, quartz glass, sapphire, or zerodur.

12. A method for manufacturing a glass product comprising the steps of:a) providing a coated or an uncoated glass surface;c) applying a protective coating based on thermoplastic polymer composition, wherein the protective coating contains an opacifier and imparts improved opacity, tack-resistance and shatterproof properties to the glass product; andd) curing the coating to obtain an opaque, tack-free shatterproof glass product.

13. The method as claimed in claim 12, wherein the composition is prepared by dispersing an opacifier in the second solvent to form a uniform dispersion; and adding the uniform dispersion to a suspension or solution comprising a styrene block copolymer, a hydrogenated tackifier, a first solvent, and an additive.

14. The method as claimed in claim 12, wherein the curing is done at temperature less than about 250°C for about 5-30 minutes.

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