Identification device having antimicrobial properties

Abstract

An identification device, preferably a wristband or adhesive label, is configured to receive identifying indicia by means of a direct thermal printer. A direct thermal layer includes antimicrobial particles embedded therein and is exposed, i.e., does not have a protective overcoat or varnish covering the direct thermal layer. The antimicrobial particles increase the surface available silver ions and are preferably formed of an aqueous dispersion of silver chloride-coated titanium dioxide particles. The antimicrobial particles may also be formed of an inorganic silver-containing compound such as silver zirconium phosphates or a silver substituted zeolite.

Description

BACKGROUND OF THE INVENTION[0001]The present invention is directed to an identification device, preferably a wristband or an adhesive label, comprising a direct thermal printable surface having antimicrobial properties. Specifically, the identification device is configured for receiving identification information by means of a direct thermal printer and having antimicrobial properties without the use of a protective layer or overcoat on top of the direct thermal layer.[0002]Direct thermal printable media is used in printers and in other applications requiring permanent imaging such as wristbands, tags, labels and other identification media. In contrast to printing technologies that involve the transfer of ink from one location to another, direct thermal printing uses a special printable media that incorporates a color developing mechanism. Images are formed by exposing the color developing mechanism to concentrations of heat that produce localized chemical reactions involving a chan...

AI Technical Summary

Benefits of technology

[0009]The present invention is directed to an identification device such as a label or a wristband that has a direct thermal reactive layer with inherent antimicrobial properties achieved without the use of a coating or varnish over the direct thermal reactive layer. The inherent antimicrobial properties are achieved by embedding an antimicrobial additive into the direct thermal reactive layer itself. In this way, the direct thermal reactive layer does not require a varnish or overcoat to protect the identification device by inhibiting bacterial growth on the surface of the label or wristband.

[0010]In a particular embodiment, the identification device includes a wristband or a label having a direct thermal face stock that has antimicrobial properties without the requirement of an additional coating or varnish layer to protect against microbial growth. The antimicrobial properties are achieved by embedding an antimicrobial additive directly into the direct thermal layer chemistry during manufacture of the direct thermal face stock. The antimicrobial additives may include an aqueous dispersion of silver chloride-coated titanium dioxide particles. The inorganic nature, small particle size, and high temperature tolerance of this “non-nano silver” antimicrobial chemistry makes it ideal for use in a wide range of printing applications. The antimicrobial direct thermal layer of an inventive identification device such as a wristband or label provides for a release of silver ions on demand, which safely inhibit bacterial growth on the identification device. There are numerous advantages to this inventive configuration, such as: no need for a varnish or overcoat to provide antimicrobial protection, a longer print head life, lower energies and higher speeds for printing processes, no buildup on the printer rollers, as well as consistent printability, scanability and readability.

Problems solved by technology

Although such silver-based agents provide suitable antimicrobial properties within thermoplastic articles, and other types of articles, there are certain limitations as to the potential antimicrobial efficacy of such thermoplastic articles.

Such limitations are apparently due to relatively low amounts of surface-available silver within and / or on such thermoplastic articles.

Without intending to be bound to any specific scientific theory, it is believed that such low surface-available amounts of silver are the result of the inability of a sufficient amount of the integrated silver compounds to migrate to the thermoplastic surface.

However, these particular methods and plastics have proven to be costly (with the high expense of benzotriazoles initially), particularly since relatively high concentrations of the expensive stabilizing compounds are required, and do not provide any appreciable increase of available silver on the surface of such articles.

Also, as these stabilizers are not thermally stable, they introduce additional processing complications.

As such, there is no teaching or fair suggestion within the prior art which pertains to the needed improvement in increasing the amounts of surface-available silver compounds on target thermoplastics.

There are several disadvantages to using an antimicrobial varnish as in the Zebra product, including: inconsistent printing due to variation in the varnish thickness, discoloration of the varnish when exposed to UV light, shorter print head life, build-up of the varnish on printer rollers, and relatively lower speeds / higher heat energy requirement for the printing process.

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