Patent Description:
Disclosed herein are an antibacterial glass composition and a manufacturing method thereof that exhibits an antibacterial property.

Microorganisms such as germs, viruses and bacteria are found in all places, in particular, a washbasin, shelves in a fridge or a washing machine that are used in our daily life. When such microorganisms invade the human body, they can infect the human body and become a serious threat to human health. Under the circumstances, there is a growing need for an antibacterial glass composition capable of controlling the spread of microorganisms to the items such as a washbasin, shelves in a fridge, an oven, a washing machine, and the like that are used in everyday life.

In the related art, an antibacterial glass composition includes molybdenum oxide, to increase the number of positive hydrogen ions that are generated from moisture and the molybdenum oxide. The water-soluble medium creates an acid environment, and microorganisms are killed in the acid environment. However, the antibacterial glass composition including mono molybdenum oxide cannot ensure water resistance properly, and the acid environment needs to be created.

To ensure sufficient water resistance, an antibacterial glass composition includes compound oxide in which molybdenum and silver or molybdenum and copper are combined. However, in the antibacterial glass composition including the compound oxide, a ratio of molybdenum decreases. Accordingly, an acid environment of the water-soluble can hardly be created, causing deterioration of antibacterial activity.

Additionally, the antibacterial glass composition including the compound oxide, in which molybdenum and silver or molybdenum and copper are combined, can cause blood clots and cytotoxicity in the human body.

A high-cost component such as silver causes an increase in the manufacturing costs of an antibacterial glass composition.

An antibacterial glass composition including <NUM> wt% or greater of ZnO is widely known. However, in the antibacterial glass composition, ZnO only exhibits antibacterial activity, and the continuous extraction of Zn is a cause for concern. Further, the durability of the antibacterial glass composition can deteriorate. <CIT> discloses an antibacterial glass composition comprising silicon oxide: <NUM>-<NUM>% by weight, boron oxide: <NUM>-<NUM>% by weight, sodium oxide: <NUM>-<NUM>% by weight, aluminum oxide: <NUM>-<NUM> wt%, zinc oxide: <NUM>-<NUM> wt%, copper oxide: <NUM>-<NUM> wt%, and silver oxide: <NUM>-<NUM> wt%.

The objective of the present invention is to provide a novel silicate-based antibacterial glass composition that ensures excellent durability and antibacterial activity. In particular, the objective of the present d invention is to provide a novel glass composition that ensures the durability and excellent antibacterial activity of the antibacterial glass composition even if the content of ZnO increases.

To achieve the above objectives, an antibacterial glass composition according to the present invention includes <NUM>-<NUM> wt% of ZnO, and other components at properly controlled composition ratios.

An antibacterial glass composition according to the present invention includes <NUM>-<NUM> wt% of SiO<NUM>; <NUM>-<NUM> wt% of B<NUM>O<NUM>; <NUM>-<NUM> wt% of ZnO; <NUM>-<NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O; <NUM>-<NUM> wt% of one or more of Al<NUM>O<NUM> and TiO<NUM>; <NUM>-<NUM> wt% of NaF; and <NUM> -<NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> wherein the antibacterial glass composition respectively comprises <NUM> wt% or greater of Co<NUM>O<NUM> and CuO. thereby causing no deterioration in durability and ensuring excellent antibacterial activity.

An antibacterial glass composition according to the present invention may ensure excellent durability and antibacterial activity.

The antibacterial glass composition may be applied to a wide range of products as an all-purpose antibacterial agent.

The antibacterial glass composition may be manufactured cost-effectively since the antibacterial glass composition includes no high-cost component.

The invention is defined in the appended claim <NUM>, directed to an antibacterial glass composition, and in the appended claim <NUM>, directed to a manufacturing method of an antibacterial glass composition. Preferred embodiments are defined in the appended dependent claims. Below, preferred embodiments according to the invention are specifically described. Embodiments are not limited to the embodiments set forth herein and can be modified and changed in various different forms. The embodiments in the invention are provided such that the invention can be through and complete and the invention can be fully conveyed to one of ordinary skill in the art. Hereafter, an antibacterial glass composition and a manufacturing method thereof according to the present invention are specifically described.

An antibacterial glass composition according to the present disclosure includes <NUM>-<NUM> wt% of SiO<NUM>; <NUM>-<NUM> wt% of B<NUM>O<NUM>; <NUM>-<NUM> wt% of ZnO; <NUM>-<NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O; <NUM>-<NUM> wt% of one or more of Al<NUM>O<NUM> and TiO<NUM>; <NUM>-<NUM> wt% of NaF; and <NUM>-<NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> wherein the antibacterial glass composition respectively comprises <NUM> wt% or greater of Co<NUM>O<NUM> and CuO.

The antibacterial glass composition is a novel silicate-based glass composition that ensures excellent durability and antibacterial activity. Hereafter, the components of the antibacterial glass composition according to the invention are described specifically.

SiO<NUM> is an essential component that forms a glass structure and serves as a skeleton of the glass structure. The antibacterial glass composition includes <NUM>-<NUM> wt% of SiO<NUM>. When greater than <NUM> wt% of SiO<NUM> is included, viscosity increases when glass melts. Accordingly, workability may deteriorate during quenching. When less than <NUM> wt% of SiO<NUM> is included, the glass structure may be weaken, and water resistance may deteriorate.

B<NUM>O<NUM> serves as a glass former together with SiO<NUM> such that a glass composition is vitrified. Since B<NUM>O<NUM> has a low melting point, B<NUM>O<NUM> helps to vitrify the glass composition easily as well as lowering a eutectic point of a molten material. The antibacterial glass composition according to the invention includes <NUM>-<NUM> wt% of B<NUM>O<NUM>. When greater than <NUM> wt% of B<NUM>O<NUM> is included, B<NUM>O<NUM> interferes with content of the other components, resulting in deterioration in the antibacterial activity. When less than <NUM> wt% of B<NUM>O<NUM> is included, the glass structure may be weaken, and the water resistance may decrease.

ZnO serves a mesh modifier as well as a mesh former in terms of the structure of glass. Additionally, ZnO is one of the main components that exhibit antibacterial activity in the composition of glass. The antibacterial glass composition according to the d invention includes <NUM>-<NUM> wt% of ZnO. In the invention, content of ZnO increases to improve the antibacterial activity. An increase in the content of ZnO in the composition of glass causes deterioration in the durability of the glass composition. In the invention, the content of the other components are adjust to prevent deterioration in the durability. When less than <NUM> wt% of ZnO is included, the antibacterial activity of the glass composition may not be ensured. When greater than <NUM> wt% of ZnO is included, the durability or thermal property of the glass composition may deteriorate.

Alkali oxides such as Na<NUM>O, K<NUM>O, and Li<NUM>O perform cross-linking in the composition of glass and serve as a mesh modifier. Some of the components may not be vitrified solely, but vitrified when mixed with the mesh former such as SiO<NUM>, B<NUM>O<NUM> and the like at a predetermined ratio. When only one of the components described above is included in the glass composition, the durability of glass may deteriorate in an area in which vitrification is possible. When two or more of the components are included in the glass composition, the durability of glass may improve depending on a ratio. The antibacterial glass composition according to the invention includes <NUM>-<NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O. When greater than <NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O is include, the thermal property of the glass composition may deteriorate. When less than <NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O is included, hydrolysis of a component such as ZnO is hardly controlled, causing deterioration in the antibacterial activity.

The antibacterial glass composition according to the invention may include 3wt% or less of Li<NUM>O, for example. When greater than 3wt% of Li<NUM>O is included, vitrification is hardly performed, and devitrification is highly likely to occur.

Al<NUM>O<NUM> and TiO<NUM> improve the chemical durability, thermal property, and the like of glass. The antibacterial glass composition according to the d invention includes <NUM>-<NUM> wt% of one or more of Al<NUM>O<NUM> and TiO<NUM>. When less than <NUM> wt% of one or more of Al<NUM>O<NUM> and TiO<NUM> is included, the durability, and the like of glass may deteriorate. When greater than <NUM> wt% of one or more of Al<NUM>O<NUM> and TiO<NUM> is included, devitrification may occur while glass melts.

NaF controls surface tension of glass and improves surface characteristics of a glass coating.

The antibacterial glass composition according to the includes <NUM>-<NUM> wt% of NaF. When greater than <NUM> wt% of NaF is included, the thermal properties of glass may deteriorate. When less than <NUM> wt% of NaF is included, the surface characteristics of a glass coating layer may deteriorate.

Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> help glass itself to exhibit the antibacterial activity. Additionally, Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> allow of a chemical coupling between a low carbon steel substrate and glass to improve adhesion of a glass coating layer when the glass is used as a material for coating the substrate. The antibacterial glass composition according to the invention includes <NUM>-<NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM>. When less than <NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> is included, the antibacterial activity of glass may deteriorate. When greater than <NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM> is included, the durability of glass may deteriorate.

The antibacterial glass composition respectively includes <NUM> wt% or greater of Co<NUM>O<NUM> and CuO. To improve the antibacterial activity and adhesion of the antibacterial glass composition equally, Co<NUM>O<NUM> and CuO are all included in the glass composition.

Hereafter, a manufacturing method of an antibacterial glass composition according to the present invention is specifically described.

The manufacturing method of an antibacterial glass composition includes providing materials for an antibacterial glass composition; melting the materials for an antibacterial glass composition; and cooling the melted materials for an antibacterial glass composition in a quenching roller and forming an antibacterial glass composition.

The materials for an antibacterial glass composition sufficiently mix, and then melt. For example, the materials for an antibacterial glass composition may melt in a range of temperatures of <NUM>-<NUM>. Additionally, the materials for an antibacterial glass composition may melt for <NUM>-<NUM> minutes.

Then the melted materials for an antibacterial glass composition may cool rapidly using a chiller and the like in the quenching roller. As a result, an antibacterial glass composition may be formed.

Then the antibacterial glass composition according to the invention may be coated on one surface of an object to be coated. The object to be coated may be part or all of a metallic plate, a tempered glass plate, and a cooking appliance. A spray method may be used in the coating process, but not limited.

The antibacterial glass composition may be burned in a range of temperatures of <NUM>-<NUM> for <NUM>-<NUM> seconds.

Hereafter, aspects according to the invention are specifically described with reference to embodiments.

Antibacterial glass compositions having composition ratios described in table <NUM> hereunder were manufactured. A raw material for each component was sufficiently mixed in a V-mixer for three hours. Na<NUM>CO<NUM>, K<NUM>CO<NUM>, and Li<NUM>CO<NUM> were respectively used as a raw material for NazO, K<NUM>O, and Li<NUM>O. The rest components are described in table <NUM>. The mixed materials melted sufficiently at <NUM> for <NUM> minutes, and rapidly cooled in the quenching roller, to obtain a glass cullet.

To manufacture an antibacterial glass composition, initial granularity of the glass cullet obtained in the above processes was controlled with a ball mill, was ground for about five hours using a jet mill, and then passed through a <NUM> mesh sieve (ASTM C285-<NUM>) such that a particle diameter of the glass cullet was limited to <NUM> or less.

The antibacterial glass compositions in the embodiments and comparative examples were sprayed onto a low carbon steel sheet (<NUM>×<NUM>) having a thickness of <NUM> or less with a corona discharge gun. A voltage of the corona discharge gun was controlled in a range of <NUM>-<NUM> kV. An amount of the antibacterial glass composition sprayed onto the low carbon steel sheet was <NUM>/m<NUM>. The antibacterial glass composition was burned in a range of temperatures of <NUM>-<NUM> for <NUM>-<NUM> seconds, and finally, a sample having a coating layer was manufactured.

The antibacterial activity of the samples in the embodiments and comparative examples was evaluated as follows.

To ascertain the antibacterial ability of the coating layer, the antibacterial activity measurements against staphylococcus aureus and Escherichia coli was measured using the JIS Z <NUM> method (a standard test for antibacterial activity) that is a film attachment method. The antibacterial activity measurements are ordinarily <NUM> or greater, and is converted with respect to <NUM>% of the antibacterial ability. The conversion method is specifically described as follows.

As shown in table <NUM>, the embodiments according to the invention exhibit excellent antibacterial activity.

The antibacterial activity of comparative example <NUM> is inferior to the antibacterial activities of the embodiments. In comparative example <NUM>, the coating layer separated from the substrate since a thermal expansion coefficient of the coating layer does not match a thermal expansion coefficient of a base material of the substrate. Thus, it was impossible to measure the antibacterial activity of comparative example <NUM>.

Claim 1:
An antibacterial glass composition, comprising:
<NUM>-<NUM> wt% of SiOz;
<NUM>-<NUM> wt% of B<NUM>O<NUM>;
<NUM>-<NUM> wt% of ZnO;
<NUM>-<NUM> wt% of one or more of Na<NUM>O, K<NUM>O and Li<NUM>O;
<NUM>-<NUM> wt% of one or more of Al<NUM>O<NUM> and TiOz;
<NUM>-<NUM> wt% of NaF; and
<NUM>-<NUM> wt% of one or more of Co<NUM>O<NUM>, CuO and Fe<NUM>O<NUM>,
wherein the antibacterial glass composition respectively comprises <NUM> wt% or greater of Co<NUM>O<NUM> and CuO.