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 with lubricating and anti-scratch properties, comprising glycidoxypropyltrimethoxysilane and phenyltriethoxysilane. The present invention further describes a 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. (canceled)

2. (canceled)

3. A pharmaceutical primary glass container having a coating comprising cross-linked glycidoxypropyltrimethoxysilane and phenyltriethoxysilane.

4. The pharmaceutical primary glass container according to claim 3, wherein said coating has a thickness of less than 50 nm.

5-10. (canceled)

11. The pharmaceutical primary glass container according to claim 3, wherein the coating is formed from a varnish product comprising glycidoxypropyltrimethoxysilane and phenyltriethoxysilane.

12. The pharmaceutical primary glass container according to claim 11, wherein the glycidoxypropyltrimethoxysilane and the phenyltriethoxysilane are each in a weight percentage from 2% to 8%.

13. The pharmaceutical primary glass container according to claim 11, wherein the varnish product further comprises HCl (0.1N) in a weight percentage from 1% to 2%, and a photoinitiator in a weight percentage from 0.1% to 1%.

14. The pharmaceutical primary glass container according to claim 11, wherein the varnish product further comprises a solvent, and wherein the solvent is either ethanol or propylene glycol methyl ether.

15. The pharmaceutical primary glass container according to claim 14, wherein the solvent is ethanol.

16. The pharmaceutical primary glass container according to claim 14, wherein the solvent is propylene glycol methyl ether.

17. The pharmaceutical primary glass container according to claim 3, wherein the coating is formed from a varnish product comprising: glycidoxypropyltrimethoxysilane in a weight percentage from 2% to 8%; phenyltriethoxysilane in a weight percentage from 2% to 8%; solvent in a weight percentage from 60% to 96%; HCl (0.1N) in a weight percentage from 1% to 2%; and photoinitiator in a weight percentage from 0.1% to 1%.

19. The pharmaceutical primary glass container according to claim 17, wherein the solvent is ethanol.

20. The pharmaceutical primary glass container according to claim 17, wherein the solvent is propylene glycol methyl ether.

Description

[0013] 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 and resistance to mechanical damage.

[0014] Within the scope of such technical task, an object of the present invention is to provide a glass product with anti-scratch, sliding and transparency properties, hence increasing its compressive strength, minimizing the quantity of defects on its surface which can act as precursors to fractures. 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.

[0015] Last but not least, an object of the present invention is to provide a coating with anti-scratch properties and resistance to mechanical damage within the context of an eco-compatible production process.

[0016] The technical task and such objects according to the present invention are reached through the provision of a coating with lubricating and anti-scratch properties, characterized in that it comprises glycidoxypropyltrimethoxysilane and phenyltriethoxysilane.

[0017] The present invention further describes a glass product that implements such coating and a pharmaceutical primary glass container that implements such coating.

[0018] The present invention further describes a varnish product for producing such coating, characterized in that it comprises glycidoxypropyltrimethoxysilane and phenyltriethoxysilane and a solvent. Advantageously, said varnish 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.

[0019] Last but not least, the present invention describes a method for protecting a glass surface of a glass product characterized in that it comprises a step of applying such varnish product.

[0020] 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.

[0021] 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. After the synthesis of the varnish, the coating will be performed through spray coating or immersion coating with a specific machine.

[0022] The coating applied in this way is then hardened.

[0023] 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 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.

[0024] 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.

[0025] 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.

[0026] Specific embodiments of the production process of the coating and the application thereof according to the present invention are described below.

Configuration A

[0027] Such configuration consists of a single-layer coating.

[0028] The general formulation of the varnish product contains: [0029] glycidoxypropyltrimethoxysilane due to its mechanical properties [0030] phenyltriethoxysilane due to its thermal stability

Configuration A—Synthesis of the Varnish

[0031] A varnish formulation has been developed based on a mixture between glycidoxypropyltrimethoxysilane and phenyltriethoxysilane. The implied solvent (ethanol or propylene glycol methyl ether) depends on the coating process used: [0032] For immersion coating, ethanol is used as the solvent. [0033] For spray coating, propylene glycol methyl ether is used as the solvent.

[0034] The different weight percentages in the general formulation of the varnish are listed below:

TABLE-US-00001 Compound Percentage by weight Glycidoxypropyltrimethoxysilane 2-8.00% Phenyltriethoxysilane 2-8.00% Solvent (propylene glycol methyl ether or 60-96.0%  ethanol according to the process) HCl (0.1N)   1-2% Photoinitiator  0.1-1%

[0035] Glycidoxypropyltrimethoxysilane and phenyltriethoxysilane are hydrolyzed separately with hydrochloric acid (10%) in stoichiometric proportion for at least 1 hour under magnetic agitation at ambient temperature.

[0036] Hydrolyzed glycidoxypropyltrimethoxysilane and phenyltriethoxysilane are then mixed together and the solvent is added. The solution is agitated for a number of minutes. A photoinitiator, for example Irgacure PAG 290, is then added to the formulation. Such photoinitiator guarantees the cross-linking of the organic portions under UV light.

[0037] At this point the varnish formulation is ready to use.

[0038] The specific varnish formulations and their characteristics are listed below.

Specific Varnish Formulation A1 (Intended Use for Immersion Coating)

[0039]

TABLE-US-00002 Precursor role (3-Glycidyloxypropyl)trimethoxysilane Precursor .sup. 4% Glymo Phenyltriethoxysilane Precursor .sup. 4% Hydrochloric acid (0.1N) activator 1.9% PAG 290 UV 0.1% Photoinitiator Ethanol Solvent  90%

100 g Synthesis of Varnish Formulation A1.

[0040] Introduction of 4 g of Glymo in a first glass beaker and addition of 0.9 g of hydrochloric acid.

[0041] In a second glass beaker, addition of 4 g of phenyltriethoxysilane and 1 g of hydrochloric acid.

[0042] Mixture of the beakers for 1 hour under magnetic agitation (250-300 rpm).

[0043] Mixture of the beaker with Glymo with one of phenyltriethoxysilane until homogenization (1 minute at 250-300 rpm).

[0044] Addition of 90 g of ethanol and 0.1 g of PAG 90. The solution is left for 10 minutes under magnetic agitation (250-300 rpm).

[0045] As mentioned, the varnish is then coated onto the glass substrate through immersion coating and then hardened with UV (60 seconds—mercury lamp).

Properties of the Varnish Formulation A1 (Liquid Phase)

[0046]

TABLE-US-00003 Density 0.811 Solid content 0.95% Viscosity 1.5 cP Colour/appearance Transparent/colourless Surface tension (mN/m) 21.3 pH 2.5

Specific Varnish Formulation A2 (Intended Use for Spray Coating)

[0047]

TABLE-US-00004 Precursor role (3-Glycidyloxypropyl)trimethoxysi!ane Precursor .sup. 4% Glymo Phenyltriethoxysilane Precursor .sup. 4% Hydrochloric acid (0.1N) Activator 1.9% PAG 290 UV 0.1% Photoinitiator Propylene glycol monomethyl ether Solvent  90% acetate Dowanol

100 g Synthesis of Varnish Formulation A2.

[0048] Introduction of 4 g of Glymo in a first glass beaker and addition of 0.9 g of hydrochloric acid.

[0049] In a second glass beaker, addition of 4 g of phenyltriethoxysilane and 1 g of hydrochloric acid.

[0050] Mixture of beakers for 1 hour under magnetic agitation (250-300 rpm).

[0051] Mixture of the beaker with Glymo with one of phenyltriethoxysilane until homogenization (about 1 minute at 250-300 rpm).

[0052] Addition of 90 g of Dowanol and 0.1 g of PAG 90. The GFD solution is left for 10 minutes under magnetic agitation (250-300 rpm).

[0053] As mentioned, the varnish is then coated onto the glass substrate through spray coating and then hardened with UV (60 seconds—mercury lamp).

Properties of the Vanish Formulation A2 (Liquid Phase)

[0054]

TABLE-US-00005 Density 0.973 Dry matter content 0.62% Viscosity 1.5 cP Colour/appearance Transparent/slightly yellow Surface tension (mN/m) 25.2 pH 1.6

Coating Process

[0055] 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

[0056] For glass bottles, the pretreatment process is the same for every configuration.

[0057] 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.

[0058] The bottles are coated following this treatment.

Coting

[0059] In configuration A with propylene glycol methyl ether, the coating process is performed through spray coating. In that case, the spraying is performed for 0.4 s at a pressure at the nozzle of 50 psi. While the varnish is sprayed, the bottle rotates at a speed of 480 rpm.

[0060] In configuration A with ethanol, the coating process is performed through immersion coating. In that case the extraction speed is 50 mm/min.

Hardening

[0061] After the deposition process, the coatings must be hardened under UV light with the following wavelengths, UVA (320-390 nm), UVB (280-320 nm), UVC (250-260 nm), UVV (395-445 nm) for 3 min.

[0062] 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.