COATING WITH THERMAL STABILITY AND ANTI-SCRATCH PROPERTIES, GLASS PRODUCT HAVING SUCH COATING, VARNISH PRODUCT FOR PRODUCING SUCH COATING AND METHOD FOR PROTECTING A GLASS SURFACE AND IN PARTICULAR A PHARMACEUTICAL PRIMARY GLASS CONTAINER

Abstract

The present invention describes a coating comprising at least an organic portion conferring lubricating and anti-scratch properties and at least an inorganic portion conferring thermal stability, said inorganic portion comprising titanium butoxide and said organic portion comprising fluorosilane. The present invention further describes a solvent-based varnish product for producing such coating and a glass product, in particular a pharmaceutical primary glass container having such coating. Last, but not least, a method is disclosed for protecting a glass surface.

Claims

1. A coating comprising at least an organic portion conferring lubricating and anti-scratch properties and at least an inorganic portion conferring thermal stability, wherein said inorganic portion comprises titanium butoxide and said organic portion comprises fluorosilane.

2. The coating according to claim 1, wherein said fluorosilane is a perfluoro-polyether fluorosilane.

3. The coating according to claim 1, wherein it comprises a first layer containing said organic portion and a second layer containing said inorganic portion.

4. The coating according to claim 1, wherein it comprises a single layer containing said organic portion and said inorganic portion.

5. A glass product wherein it comprises a coating according to claim 1.

6. A pharmaceutical primary glass container wherein it comprises a coating according to claim 1.

7. The pharmaceutical primary glass container according to claim 6, wherein said coating has a thickness of less than 50 nm.

8. A varnish product for making a coating, wherein it comprises titanium butoxide, fluorosilane and at least a solvent.

9. The varnish product for making a coating, wherein it comprises: a first varnish product comprising titanium butoxide and at least a solvent; and a second varnish product comprising fluorosilane and at least a solvent.

10. The varnish product for making a coating according to claim 8, wherein said at least a solvent is ethanol and/or acetic acid in combination with water.

11. The varnish product for making a coating according to claim 8, wherein it derives from a sol-gel varnish synthesis.

12. The varnish product for making a coating according to claim 9, wherein said first varnish product is a one-component varnish product with the following formulation: titanium butoxide in a range from 1 to 10% by weight, acetic acid in a range from 1 to 15% by weight, ethanol in a range from 30 to 60% by weight and water in a range from 20 to 50% by weight; and in that said second varnish product comprises an activator component and a precursor component, said activator component comprising HCl (0.1 N) in a range from 0.1 to 5% by weight, ethanol in a range from 80 to 96% by weight and water in a range from 1 to 6% by weight, and said precursor component comprising fluorosilane in a range from 1 to 15% by weight.

13. A method for protecting the glass surface of a glass product, wherein comprises a step of applying a varnish product according to claim 8.

14. The method for protecting the glass surface according to claim 13, wherein said first varnish product is applied as primer and said second varnish product is applied as finishing layer.

15. The method for protecting the glass surface according to claim 13, wherein said glass product is a pharmaceutical primary glass container produced through a NGTGC process.

16. A method of protecting substrates such as plastics, textiles, ceramics, metals and alloys wherein it comprises a step of applying a varnish product according to claim 8.

17. The method of protecting substrates according to claim 16 wherein said first varnish product is applied as primer and said second varnish is applied as top coat.

18. Glass packaging for food, beverage and personal care products, glazing, displays, optical components, lighting, eyewear, and watchmaking characterized in that of embodying a coating according to claim 1.

Description

[0010] The task of the present invention is to design a new and inventive solution with respect to the prior art which gives the glass product a transparent surface coating with anti-scratch properties, resistance to mechanical damage and thermal stability.

[0011] Within the scope of such technical task, an object of the present invention is to provide a glass product with anti-scratch, sliding, transparent and compatibility properties with significant thermal exposure, hence increasing its compressive strength, minimizing the quantity of defects on its surface which can act as precursors to fractures.

[0012] There is also the need for a method through which the improvement in anti-scratch properties of the surface of a glass container can translate into greater overall resistance to breaking of the same glass composition.

[0013] Last but not least, an object of the present invention is to provide a coating with anti-scratch properties, resistance to mechanical damage and thermal stability within the context of an eco-compatible production process.

[0014] The technical task and such objects according to the present invention are reached by providing a coating comprising at least an organic portion conferring lubricating and anti-scratch properties and at least an inorganic portion conferring thermal stability, characterized in that said inorganic portion comprises titanium butoxide and said organic portion comprises fluorosilane.

[0015] Preferably, said fluorosilane is a perfluoro-polyether fluorosilane.

[0016] In an embodiment of the invention, said coating comprises a first layer containing said organic portion and a second layer containing said inorganic portion.

[0017] In a different embodiment of the invention, said coating comprises a single layer containing said organic portion and said inorganic portion.

[0018] In one embodiment of the invention said coating has a thickness of less than 50 nm.

[0019] The present invention also describes a glass product that implements such coating, a pharmaceutical primary glass container that implements such coating and a varnish deriving from a sol-gel varnish synthesis for producing such coating.

[0020] As mentioned, the coating derives from a sol-gel varnish synthesis. Such process allows the coating properties to be modulated by selecting the appropriate precursors, synthesis conditions and coating process.

[0021] Advantageously, according to the present invention, an inorganic network of metal oxides is created to confer resistance to high temperatures and, in order to improve the resistance to scratches and abrasion, the non-polymeric organic portion is combined with the inorganic network. Such hybrid organic-inorganic materials are based on fluoro-compounds.

[0022] The present invention also provides a method for protecting a glass surface characterized in that it comprises a step of coating said glass surface with such varnish.

[0023] According to a preferred embodiment of the invention said method of protecting a glass surface comprises an activation step through a low pressure plasma treatment or atmospheric plasma treatment of the glass surface prior to the application of such varnish coating to confer wettability and adherence of the varnish product.

[0024] According to a preferred embodiment of the invention the low pressure plasma treatment is performed with a mixture of N.sub.2/H.sub.2 gas and the atmospheric plasma treatment is performed with air.

[0025] After the synthesis of the varnish, the coating will be performed through spray coating or immersion coating with a specific machine.

[0026] The coating applied in this way is then hardened.

[0027] In a preferred embodiment of the present invention, pharmaceutical primary glass containers produced through an NGTGC process are subsequently coated with an anti-scratch coating in compliance with the present invention. The resulting pharmaceutical primary glass containers demonstrate greater long-lasting break strength than primary containers that are not treated with the coating according to the invention. It is therefore considered that this is due to the fact that the NGTGC process confers greater break strength and the coating according to the present invention prevents scratches occurring, hence freezing the advantages of the NGTGC process in that way also when the primary containers are further packaged and used in a standard filling line, in which they are exposed to contact between containers, but also contact with metal parts.

[0028] The coating made according to the present invention shows thermal resistance up to 330 C.

[0029] Advantageously, the coating made according to the present invention is ecological, which means that the compounds used in the design of the formulation comply with REACH and do not present safety risks.

[0030] Naturally, a coating according to the present invention may be used for making glass containers for pharmaceutical applications such as bottles, cartridges, syringes or vials for preventing mechanical damage or breaking, but may also be used in other fields of application such as glass packaging for food and drink and products for personal hygiene, windows, screens, optical components, lighting, glasses and watches. Furthermore, the present invention may be applied on other substrates such as plastics, fabrics, ceramics, metals and alloys in which anti-fingerprint tribological properties and/or high thermal properties are to be obtained.

[0031] According to an embodiment of the invention, in this method of protecting substrates such as plastics, textiles, ceramics, metals and alloys, said first varnish product is applied as primer and said second varnish is applied as top coat.

[0032] According to an embodiment of the invention, a glass packaging for food, beverage and personal care products, glazing, displays, optical components, lighting, eyewear, and watchmaking is characterized in that of embodying an above referred coating.

[0033] Specific embodiments of the production process of the coating and the application thereof according to the present invention are described below.

[0034] The following configurations have been used in order to combine thermal properties and mechanical properties.

Configuration A

[0035] Such configuration consists of a multi-layer coating: [0036] a primer layer of titanium butoxide, metal mesh for improving adherence and thermal stability [0037] a finishing layer of fluorosilane network for improving the mechanical properties such as lubrication or scratch resistance

Configuration ASynthesis of the Varnish

Synthesis of the First One-Component Varnish Product

[0038] An inorganic solution was used. It comprises precursors of titanium alcoxides.

[0039] The weight percentages of different elements of the general formulation are listed below:

TABLE-US-00001 Titanium butoxide 1-10% H.sub.2O 20-50% Ethanol 30-60% Acetic acid 1-15%

[0040] Titanium butoxide and acetic acid are mixed and agitated for an hour.

[0041] Ethanol and water are subsequently added to the solution. The solution is agitated for 24 hours.

[0042] The solution is ready for use.

[0043] Such solution has a pH between 2 and 3, a viscosity between 3 and 4 cP, a dry matter content between 1 and 2% and a particle diameter between 20 and 35 nm.

Synthesis of the Second Two-Component Varnish Product

[0044] In order to guarantee lubricating properties, fluorosilane was used, an organosilane containing fluorine atoms. Before being used, the fluorosilane must be hydrolyzed.

[0045] The weight percentages of different elements of the general formulation are listed below:

TABLE-US-00002 Fluorosilane 1-15% H.sub.2O .sup.1-6% HCl (0.1N) 0.1-5% Ethanol 80-96%

[0046] The varnish activator component is formed by mixing ethanol, water and HCl (0.1 N).

[0047] The precursor component of the varnish is added to the activator component and all the components are mixed together and shaken for an hour prior to use.

[0048] Such solution has a pH between 2 and 3, a viscosity between 3 and 4 cP and a dry matter content between 1 and 2%.

[0049] For such configuration, the first and second varnish products are used separately for making the multi-layer coating.

[0050] A specific formulation of the varnish and its characteristics for the first and second varnish product are listed below.

TABLE-US-00003 1st varnish 2nd varnish product product Hydrochloric acid (0.1N) Activator 1% Ethanol Solvent 44% 94% Titanium(IV) n-Butoxide Precursor 5% Glacial acetic acid (99%) Activator 11% Distilled water Activator/Solvent 40% 4% Fluorolink FS10 Precursor 1%

100 g Synthesis of Specific-Formulation Varnish

[0051] Synthesis of the first varnish product.

[0052] Add 11 g of acetic acid to a beaker.

[0053] Under strong magnetic agitation (450-500 rpm), add the titanium precursor drop by drop (5 g).

[0054] Leave under agitation for 1 h (450-500 rpm).

[0055] Add ethanol (44 g) then water (40 g) with a flow rate of 600 mL/min, maintain agitation (450-500 rpm).

[0056] Leave the solution under agitation for 24 h (250-300 rpm).

[0057] Synthesis of the second varnish product.

[0058] Add 94 g of ethanol in a beaker, add 4 g of distilled water and 1 g of hydrochloric acid.

[0059] Leave the solution for 1 min to homogenize (250-300 rpm).

[0060] Add 1 g of Fluorolink FS10 and leave under agitation for 1 hour (250-300 rpm).

[0061] The first varnish product is coated as a primer layer through spraying onto the glass substrate, subsequently, the second varnish product is coated as a finishing layer. Thermal hardening is then performed at 150 C. for 15 min.

Properties of the Specific Varnish Formulation (Liquid Phase)

[0062]

TABLE-US-00004 1st varnish product 2nd varnish product Density 0.924 0.806 Dry matter content 0.39% 0.38% Viscosity 3.8 cP 1.5-1.7 cP Colour/appearance Transparent/slightly turbid turbid Surface tension (mN/m) 26.8 18.7 pH 2.9 2.4 Particle size 20-30 nm n.a

Configuration B

[0063] Such configuration consists of a single-layer coating.

[0064] The varnish product contains: [0065] mixture of titanium butoxide and fluorosilane network.

Configuration BSynthesis of the Varnish

[0066] The weight percentages of different elements of such varnish formulation are listed below:

TABLE-US-00005 Titanium butoxide 2-10% Acetic acid 5-20% Ethanol 30-60% Water 30-50% Fluorosilane 0.1-1%

[0067] The titanium butoxide is hydrolyzed as described in the synthesis of TiO.sub.2 (configuration A). At the end of the hydrolysis of titanium butoxide, fluorosilane Fluorolink FS10) is added to the solution without any pretreatment.

Coating Process

[0068] The process described below refers to pharmaceutical primary glass containers only by way of example, since the application may, as mentioned, also include other types of substrates.

Cleaning/Degreasing

[0069] For glass bottles, the pretreatment process is the same for every configuration.

[0070] Before being coated, each bottle is degreased with fabric and ethanol. Subsequently, the bottles are treated by atmospheric plasma with air for 30 s. In a different embodiment, a low pressure plasma treatment with a mixture of N.sub.2/H.sub.2 gas may be performed.

[0071] The bottles are coated following this treatment.

Coating

[0072] The coating process depends on the formulation and on the configuration.

[0073] Configuration A consists, as mentioned, of a double-layer coating. The layer of primer comprising TiO.sub.2 is performed through spraying (4 s at 50 psi with a rotation speed of 480 rpm), then the bottle is kept in rotation at 400 rpm for 10 s and the finishing layer containing fluorosilane is performed through spray coating for 4 s at 480 rpm with a pressure of 50 psi.

[0074] In configuration B based on the formulation of TiO.sub.2 and fluorosilane the coating process is performed through spray coating for 4 s, at a rotation of 480 rpm and a pressure at the nozzle of 50 psi.

Hardening

[0075] After the deposition process, the coating is hardened at 150 C. for 15 min.

[0076] It is to be understood that changes and variations that are not beyond the scope of the invention as defined in the appended claims may be made to the coating and to the related production method described and illustrated herein.