MULTIPLE-USE DRINKING STRAWS AND THEIR PRODUCTION

Abstract

The present invention deals with a tube (1) with a tube base body (2) which consists of glass, wherein at least the inside of the tube base body (2) is at least partially covered a hydrophobic coating (3). The use of such tubes (1) as drinking straws leads to multiple use, ecologically friendly drinking straws which meet hygienic requirements and have a good cleanability. The present invention also deals with a process for producing such tubes.

Claims

1. Tube adapted to be used as a drinking straw with a tube base body which is made of or consists of glass, wherein at least the inside of the tube base body is at least partially covered with a hydrophobic coating, wherein the glass tube body is hydrophobized, preferably silanized, at least at the portions covered by the hydrophobic coating, wherein the coating additionally contains an antibacterial agent.

2. Tube according to claim 1, wherein the inside of the tube base body is fully covered with a hydrophobic coating.

3. Tube according to claim 1, wherein the tube body is made of soda lime glass, borosilicate glass or quartz glass.

4. Tube according to claim 1, wherein the coating comprises a hydrophobic polymeric material, wherein the hydrophobic polymeric material is preferably selected from the group consisting of silanes, silicone oils, halogenated hydrocarbons and hydrophobic anorganic-organic hybrid polymers.

5. Tube according to claim 1, said antibacterial agent being selected from the group consisting of silver, preferably elemental or colloidal silver, compounds of silver, preferably silver nitrate, and copper and its compounds.

6. Tube according to claim 1, said tube having an inner diameter between 3 and 10 mm, preferably between 5 and 8 mm, and/or a wall thickness between 0.8 and 3 mm, preferably between 1 and 2 mm, and/or a length between 100 and 350 mm, preferably between 120 and 300 mm, and/or wherein the coating has a thickness of between 0.1 μm and 1000 μm, preferably between 1 μm and 500 μm, more preferably between 10 μm and 100 μm.

7. Tube according to claim 1, the tube body having a straight cylindrical shape or an angled cylindrical shape or a kinked cylindrical shape.

8. Process for producing a coated glass tube comprising the following steps: a) providing a glass tube base body; b) providing a solution or suspension containing a hydrophobic polymer material; c) contacting the tubular body and the solution or suspension provided in step b) with at least the inner surface of the tubular body by immersing the tubular body 2 in the solution or suspension; d) optionally drying the tubular body obtained in step c); e) heat treating the tube obtained in step c).

9. Process according to claim 8, wherein the solution provided in step b) is a solution containing 0.5 to 10% by weight of hydrophobic polymer material, preferably 1.0 to 2.0% by weight, wherein the solvent is preferably water, and/or wherein the hydrophobic polymer material is selected from the group consisting of silanes, silicone oils, halogenated hydrocarbons and anorganic-organic hybrid polymers.

10. Process according to claim 8, the solution in step b) further containing an antibacterial agent, preferably selected from the group consisting of silver, copper and their compounds, preferably being elemental or colloidal silver or silver nitrate.

11. Process according to claim 8, wherein in step d) a temperature of at least 200° C., preferably at least 250° C., more preferably at least 300° C., is used, and/or wherein the heat treatment in step d) is carried out for at least 5 minutes, preferably at least 15 minutes, more preferably at least 30 minutes, even more preferably at least 60 minutes.

12. Process according to claim 8, wherein step c) comprises immersing the tube in the solution provided in step b) or vaporizing the tube with the solution provided in step b) or surface diffusion.

13. Use of a tubular base body made of glass with a hydrophobic coating as drinking straws.

Description

[0082] In the disclosure of the following preferred, but non-limiting embodiments of the invention are described in detail, also by referenced enclosed drawings.

[0083] FIG. 1 is a cross-sectional view of a first embodiment of a glass tube according to the present invention.

[0084] FIG. 2 is a cross-sectional view of the second embodiment of a glass tube according to the present invention.

[0085] FIG. 3 is a cross-sectional view of the third embodiment of a glass tube according to the present invention.

[0086] FIG. 1 shows a cross-sectional view of the tube 1 according to a first embodiment of the present invention, comprising a tube base body 2 and a hydrophobic coating 3. Herein, it is shown that the hydrophobic coating 3 is applied to the inner surface of the tube base body 2. Herein, the hydrophobic coating can consist of a silane, a silicone oil, a halogenated hydrocarbon or an anorganic-organic hybrid polymer as disclosed herein.

[0087] For example, silicone oils by the company Wacker can be used. Said silicone oils have a very efficient cost-benefit ratio and allow for easy handling, and a good hydrophobization of a surface can be achieved.

[0088] Furthermore, different types of Dynasilan® fabricated by Evonik Industries can be used, which provide excellent hydrophobic properties.

[0089] Furthermore, different types of Baysilon® M100 can be used.

[0090] Furthermore, chlorinated or chlorinated hydrocarbons could serve as coating, for example Teflon®.

[0091] Another particular embodiment to be exemplified for the hydrophobic coating are different types of anorganic-organic hybrid polymers like Ormocer®. Such hybrid polymeric materials can be synthesized by a sol-gel process according to which the monomer or pre-condensed components (in general, optionally organo-modified silanes, partially in combination with additional metal-alkoxy compounds and/or other compounds) are subjected to hydrolysis and condensation of the appropriate groups (see U.S. Pat. No. 7,687,654 B2).

[0092] For example, via a targeted hydrolysis and a condensation of organically modified Si-alkoxides, an anorganic network is primarily built. Furthermore, a co-condensation with other metal alkoxides, e.g. Ti, Zr or Al-alkoxides, is also possible. In a subsequent step, the polymerizable groups fixed to an anorganic network are cross-linked to each other. Furthermore, organically modified Si-alkoxides can be used, which do not participate in any organic polymerization reaction and hence contribute to an organic functionalization of anorganic networks. Such polymers can be used for functionalization of surfaces to a great extent.

[0093] FIG. 2 shows a second embodiment of the present invention. Herein, antibacterial agents 4 are incorporated in the coating 3. Said antibacterial agents can be provided as particles of a material selected from the group comprising silver, copper and their respective compounds and titanium dioxide. For example, elemental or colloidal silver can be incorporated into the coating 3. Also, the antibacterial agent can be silver nitrate, which however can be solved and homogenously distributed in the coating 3.

[0094] FIG. 3 shows a further embodiment of the present application, which shows a coating layer 3 inside and outside the tube base body. In this case, the whole drinking straw would be protected with a hydrophobic coating 3.

[0095] In the following, furthermore a process for the production of a coated glass tube according to one of the three above depicted embodiments should be presented.

[0096] Said process provides the step of providing a glass tube body 2 and a solution or suspension containing a hydrophobic polymer material, said hydrophobic polymer material defined as above. Then, the tubular body is contacted with the solution or suspension, at least the inner surface of the tubular body is contacted. With regard to the third embodiment, the whole glass tube body is contacted with the solution or suspension comprising a hydrophobic polymer material.

[0097] Afterwards, the tubular body is optionally dried.

[0098] Finally, the tubular body is heat-treated, typically at a relatively high temperature still acceptable for the coating material, for example at a temperature of at least 200° C., more preferably at least at 250° C., even more preferably at least at 300° C. in order to fix the coating to the glass surface. The heat treatment time is typically at least 5 minutes, preferably at least 15 minutes, more preferably at least 30 minutes, even more preferably at least 60 minutes. To obtain a viscosity beneficial for the coating process, the aqueous solution contains between 0.5 to 10%-wt. of the hydrophobic polymer material, preferably 1.0 to 2.0%-wt. The solvent is preferably water. However, also other solvents, in particular organic solvents, are possible.

[0099] Preferably, the contacting of the glass tube body and the solution or suspension comprises immersing the tube 2 in the solution. This dip coating is very easy and cheap, and furthermore, the whole surface of the drinking straw can be contacted with hydrophobic polymer solution or suspension.

[0100] In another embodiment, the solution or suspension comprising the hydrophobic polymer is vaporized and sprayed onto the glass tube. If only the inner side should be contacted, a spraying nozzle might be inserted into the glass tube body and moved along the glass tube body in order to guarantee homogenous coating.

[0101] In another alternative embodiment, the glass tube base body is contacted with the hydrophobic polymer by a surface diffusion process.

[0102] The present invention is not limited to the above-mentioned embodiments. The tube, by virtue of a correspondingly shaped tube base body, can also have a triangular, square or rectangular cross-section, even a polygonal or elliptic cross-section.

[0103] Also, it is possible to only apply the hydrophobic coating to a part of the interior of the tube, hence for example, a certain range can be un-coated, for example 0.5 cm at the upper and the lower end.

[0104] The tubes according to the present invention can be highly beneficially applied as drinking straws.