WO2016060624A1

WO2016060624A1 - Aromatic foam glass and its production method

Info

Publication number: WO2016060624A1
Application number: PCT/TH2014/000049
Authority: WO
Inventors: Phalatt LEOWKIJSIRI; Supalak KHUEANPHET; Panida PROMPINIT; Wiyong Kangwansupamonkon; Nuttaporn PIMPHA; Rungroj MAOLANON; Duangkamon VIBOONRATANASRI
Original assignee: Leowkijsiri Phalatt
Priority date: 2014-10-16
Filing date: 2014-10-16
Publication date: 2016-04-21
Also published as: CN107074625A; CN107074625B

Abstract

The present invention is related to an aromatic foam glass and its production method wherein said aromatic foam glass comprising a body wherein said body comprises adhered glass particles of size of no more than 75 microns and having bulk density of between 0.19 g/cm3 and 0.4 g/cm3 and a porosity of between 85% and 91 %, a plurality of pores formed within said body wherein each of said plurality of pores has a size in range substantially between 0.1 mm and 2.0 mm, which can be uniformly or randomly distributed throughout said body, and an essential oil mixture wherein said essential oil mixture is infused into said body of the aromatic foam glass. With unique essential oil mixture formulations and novel production method, the resulting invention is the long-lasting aromatic foam glass that can effectively store, endure, and release any type of scents for anti-pest, aroma therapeutic, or decorative purposes.

Description

Title of the Invention

AROMATIC FOAM GLASS AND ITS PRODUCTION METHOD Field of invention

The invention relates to an aromatic foam glass and its production method. More particularly, the present invention relates to a foam glass with infused essential oil mixture to be used as a pest repellant or fragranced material for hygienic or therapeutic purposes that can be placed indoors, such as inside workplaces, residences, and spas, as well as outdoors, such as in plant pots, gardens, schoolyards and parks.

Background of the invention The present invention relates generally to an aromatic foam glass to be used as a pest repellent or a fragranced material wherein said aromatic foam glass are produced from glass particles or glass wastes and are infused with essential oil mixture. The essential oil used in said mixture is preferably chosen from plant-based essential oils with insect repellent properties such as citronella oil, lemongrass oil, and eucalyptus oil. There are three common types of porous materials that are used to absorb and store various substances: porous rock, clay, and foam glass. Porous rock is a natural rock characterizes by large number of pores that are caused by natural corrosion. These pores are merely presented on the outer surface and often distributed randomly. However, most common problems with the porous rocks are their difficulty to reshape, heavy weight, low porosity, inability to be colored. Clay has leveled surface and moderate porosity. It is also shapeable with an aid of certain tool and can be colored to some extent. Foam glass, on the other hand, looks very similar to a sponge, but cannot be pressed or subsided. The foam glass also has relatively light weight, uniformly distributed pores, high porosity and can be shaped and colored according to one's needs. Foam glass, thus, has many desirable properties to be used as an effective absorbent or a material to encapsulate substances and slowing their rate of evaporation.

Plant-based essential oils or chemicals are popularly used for many purposes ranging from aromatherapy and hygienic purposes such as to reduce stress, relax muscle, heal wound, or elevate mood once applied as droplets or sprayed on skin, during bathing, or by inhalation through steaming with water mixture on some device, to repel against pests such as insects, bugs, or mosquitos that can damage crops, properties, or cause annoyance or even serious allergic reactions in some people. Recently, there have been many inventions aiming to create products based on various essential oil compositions to serve as effective repellents such as in the liquid compositions of lavender oil, lemongrass oil, tea tree oil, thyme oil, ethanol, and water of CN102579288, an antiparasitic formulation comprising eucalyptus oil, cajeput oil, lemongrass oil, clove bud oil, peppermint oil, piperonyl and piperonyl butoxide of EP1 196034, and a mosquito repellent composition comprising eucalyptus oil, lemongrass oil, pomelo peel oil, wood dust, basil leave, and water of TH0703000166. Other inventions have included mixing essential oils in emulsions and capsules to help increase the shelf-life of products up to 1 -2 months, or employed the use of porous silica based material to support a pest repellent as in JP200063201 and polymer based (mainly polyethylene polymer) material to support or be infused with a mixture of essential oils as in US4713291.

Unlike the previous inventions, the present invention has identified novel method of combining a foam glass with high porosity with an essential oil mixture having therapeutic and anti-pest properties in order to create a long-lasting aromatic foam glass that can effectively store, endure, and release any type of scent generated by said essential oil mixture.

Summary of the invention

An aromatic foam glass and its production method as described in the present invention comprising a body of adhered glass particles, a plurality of pores within said body and an essential oil mixture wherein said essential oil mixture is infused into said body of the aromatic foam glass. The aromatic foam glass is generally produced through series of steps of combining glass particles with additive and foaming agent, dehumidifying and heating the glass mixture sample, placing said sample, after cooling, in a vacuum chamber containing the essential oil mixture, and conducting high pressure vacuuming to infuse said essential oil mixture into the body of said sample.

Brief description of the drawings

FIG. 1 is a graph showing the evaporation time (in hours) on x-axis and the aroma signal strengths of comparative aromatic products using E-nose technique on y-axis (as vector-based distances from control). Comparative products are consisting of aromatic foam glass samples AFG1 and AFG2 (solid lines with square and diamond shaped markers) versus commercially available products: CSl (solid line with triangle markers), an aroma oil compressed in circular gel; CS2 (dotted line with square markers), aroma oil compressed in circular gel; and CS3 (solid line with circle markers), a natural salt aggregate coated with aroma oil. All are tested under under 40°C condition.

FIG. 2 is a graph showing aroma signal strengths of seven citronella oil mixture compositions (lc-7c) tested up to 17 hours at 40°C condition, using E-nose technique.

Composition lc (solid line with diamond marker) consists of mixture of citronella oil and ethanol;

Composition 2c (solid line with square marker) consists of mixture of citronella oil, ethanol, polyethylene glycol 35000 (PEG 35000), gel wax, and distillates;

Composition 3c (solid line with triangle marker) consists of mixture of citronella oil, ethanol, PEG 35000, gel wax (half of gel wax of Composition 2c), and distillates;

Composition 4c (solid line with double cross marker) consists of mixture of citronella oil, ethanol, and PEG 35000;

Composition 5c (solid line with triple cross marker) consists of mixture of citronella oil, ethanol, PEG 35000, and PEG 1450;

Composition 6c (solid line with circular marker) consists of mixture of citronella oil, ethanol, PEG 35000, PEG 1450, gel wax, and distillates;

Composition 7c (solid line with plus-sign marker) consists of mixture of citronella oil, ethanol, PEG 35000, PEF 1450, gel wax (half of gel wax of Composition 6c), and distillates.

FIG. 3 is a group of graphs showing the storage time (in hours) on x-axis and the percentage weight of citronella oil mixture samples versus eucalyptus, lavender, orange, and jasmine oil mixture samples on y-axis.

FIG. 4 A is a graph showing the storage time (in weeks) on x-axis and the aroma strength of aromatic foam glass of this invention on y-axis, under 25 °C condition (crossed line) and 40°C condition (solid line) using E-nose technique.

FIG. 4B is a graph showing the storage time (in weeks) on x-axis and the percentage weight of aromatic foam glass of this invention on y-axis, under 25°C condition (crossed line) and 40°C condition (solid line) using E-nose technique. FIG. 5 A is a table showing mosquito (Culex quinquefasciatus) repelling efficiency rate of foam glass samples infused with citronella oil mixture (AFG).

FIG. 5B is a table showing mosquito {Culex quinquefasciatus) repelling efficiency rate of foam glass samples infused with citronella oil mixture (AFG) versus citronella oil mixture solution, and 100% pure citronella oil.

Detailed description of the invention

Foam glass as described in this invention is including, but not limited to cellular glass, cellulated glass, expanded glass, glass foam, or porous glass. According to definition by Cellular ceramic book, Glass Foams, P158-175, M. Scheffler, P.Colombo, Wiley-VCH 2005: Glass foam is generally obtained by the action of a gas-generating agent (termed gasifier or foaming agent, mostly carbon or cabonatceous substances),which is ground together with the starting glass to a finely divided powder. The mixture of glass powder, foaming agent and occasionally other mineral agent is heated to a temperature at which the evolution of glas foam the foaming agent occurs within a pyroplastic mass of the softened glass particles undergoing viscous flow sintering. The evolved gas leads to a multitude of initially spherical small bubles which, under the increasing gas pressure, expand to a foam structure of polyhedral cells that after cooling of the glass, constitute the pores in the glass foam.

The aromatic foam glass as described in this invention comprising: a body wherein said body comprises adhered glass particles of size of no more than 75 microns with bulk density of between 0.19 g/cm³ and 0.4 g/cm³ and a porosity of between 85% and 91%; a plurality of pores formed within said body wherein each of said plurality of pores has a size in range substantially between 0.1 mm and 2.0 mm, which can be uniformly or randomly distributed throughout said body; and an essential oil mixture wherein said essential oil mixture is infused into said body of the aromatic foam glass.

The essential oil mixture generally comprising 1% to 4% by weight of a gel wax, 20% to 35% by weight of an essential oil, 10% to 15% by weight of polyethylene glycol (PEG), 7% to 10% by weight of distillates, and 45% to 55% by weight of ethanol based on the total weight of said essential oil mixture. The essential oil is chosen from plant-based essential oil with aroma-therapeutic and/or pest resistant properties including, but not limited to, one or more of the following: citronella oil, lemongrass oil, citrus oil, orange oil, eucalyptus oil, tea tree oil, kaffir lime leaf oil, lavender oil, vetiver oil, basil oil, thyme oil, menthol oil and peppermint oil.

More specifically, the essential oil mixture is a citronella oil mixture with pest resistant properties comprising 2% to 4% by weight of the gel wax, 20% to 35% by weight of the citronella oil, 10% to 12% by weight of polyethylene glycol (PEG), more specifically 2% to 4% by weight of PEG at molecular weight of 35000 and 6% to 8% by weight of PEG at molecular weight of 1450, 7% to 10% by weight of the distillates, chosen from mineral spirits, kerosene, white spirits, naphtha, and/or Stoddard solvent, and 48% to 55% by weight of ethanol based on the total weight of said citronella oil mixture.

A method of producing the aromatic foam glass as described in this invention generally comprising:

- taking waste glasses and/or dried glass slushes and crushing in an industrial edge runner until said waste glasses and/or glass slushes turn into small glass particles;

- selecting said glass particles of no more than 75 microns by vibrating through a sieve;

- combining 80% to 90% by weight of said glass particles with 1% to 2 % by weight of a foaming agent, and 9% to 12% by weight of an additive, such as fluxing agent, colorant, strengthener or binding agent, based on the total weight of a glass mixture sample;

- placing said sample in a mold and dehumidifying and heating said sample at a first elevated temperature of 60-80 °C and a second elevated temperature of 700-900 °C at a rate of 1-10 °C per minute for 20-30 minutes;

- letting the sample cool down to room temperature for at least 10 hours in a furnace;

- cutting cooled sample into size and shape as required;

- putting the cooled sample in a container and pouring the essential oil mixture into said container to fill at least one fourth (1/4) of said cooled sample; and

- placing said container in a vacuum chamber and conducting vacuuming below 0.1 bar for 15-60 minutes at room temperature. The fluxing agent used in said method is chosen from one or more of the following:

Iron oxide (Fe203), sodium hydroxide (NaOH), sodium oxide (Na20), potassium oxide (K20), calcium oxide (CaO), Magnesium oxide (MgO), boron oxide (B203), cerium oxide (Ce02), sodium borate (Na2B407) and sodium hydrogen phosphate (Na2HP04). The colorant used in said method is chosen from one or more of the following:

Iron oxide (Fe203), cobalt oxide (Co304), copper oxide (CuO), copper(II)oxide (Cu20), copper sulfate (CuS04), manganese oxide (Mn02), chromium oxide (Cr203),and zinc oxide (ZnO).

The strengthener used in said method is chosen from one or more of the following: Silicon carbide (SiC), titanium oxide (Ti02), boron oxide (B203), aluminum oxide

(A1203), sodium borate (Na2B407), sodium hydrogen phosphate (Na2HP04) and boric acid (H2B03).

The binding agent used in said method is chosen from one or more of the following: sodium silicate solution (Na2Si307) and kaolin clay. E-nose technique was used in the studies as implicated in the results of FIG.1 , FIG.2,

FIG.4A and FIG.4B whereby said technique generally comprising the following steps: (1) preparing each sample in a vial or tube and connecting it to an E-nose apparatus; (2) measuring aroma strength of each sample for at least 30 times; (3) cleaning the sensor of E-nose apparatus after each time by allowing said apparatus to test with a control (air sample in vial) until the measurable signal is closest to normal air; (4) taking all raw data and translating into xyz coordinates and comparing to the coordinates of control (air sample without any aroma) that can be used as reference point; (5) taking all coordinates of all samples to find mean values (measured as vector-based distances from reference point that can be translated into graphical representations). FIG.1 illustrates the aroma strengths of comparative aromatic products using said E- nose technique whereby the aroma strengths of aromatic foam glass samples (AFG1 and AGG2) are significantly greater than aromatic strengths of conventional products across the testing period of 80 hours at 40°C condition. The conventional products tested are: CSl (solid line with triangle markers), an aroma oil compressed in circular gel; CS2 (dotted line with square markers), aroma oil compressed in circular gel; and CS3 (solid line with circle markers), a natural salt aggregate coated with aroma oil. At the final point (80 h) of testing, the aromatic signal of AFG 1 was at 8.43 (49% reduction in aroma signal from starting point), AFG 2 was at 11.26 (33% reduction), whereas the conventional products at final point were: CS1 at 2.42 (84% reduction), CS2 at 2.42 (85% reduction), and CS3 at 2.74 (75% reduction). FIG.2 depicts aroma strengths of seven citronella oil mixture compositions (lc-7c) tested up to 17 hours at 40°C condition, using E-nose technique whereby changes in aroma strength as percentage changes in vector-based distances from starting point (0 h) to final point (17 h) were as follows: Composition lc at 58% reduction, Composition 2c at 52% reduction, Composition 3c at 41% reduction, Composition 4c at 43% reduction, Composition 5c at 48% reduction, Composition 6c at 30% reduction, and Composition 7c at 40% reduction. From such findings, Composition 6c, which consists of mixture of citronella oil, ethanol, PEG 35000, PEG 1450, gel wax, and distillates, appeared to exhibit the greatest aroma retention rate as compared with 6 other citronella oil mixture compositions.

FIG. 3 illustrates the storage time (in hours) on x-axis and the percentage weight of citronella oil mixture samples versus eucalyptus, lavender, orange, and jasmine oil mixture samples on y-axis, all of which containing same mixture of PEG 35000, PEG 1450, gel wax and distillates. The weights of all samples in vials were normalized and measured across the time points to analyze any differences in percentage weights. The test was designed to measure the stability of similar compositions, but that contain different essential oils, which provide implications to their aroma strengths. The results has clearly shown that the compositions are compatible with all experimented essential oils and can be used as essential oil mixture composition for various types of substrates, especially aromatic foam glass as described in this invention.

FIGS. 4 A and 4B illustrate the storage time (in weeks) on x-axis and the aroma strength and percentage weight of aromatic foam glass of this invention on y-axis, under 25°C condition (crossed line) and 40°C condition (solid line) using E-nose technique. Aromatic foam glass under 25°C condition is found to have longer shelf-life than at 40°C condition. Nevertheless, even at 40°C condition, the reduction in both aroma strength and weight only dropped slowly when the essential oil mixture is embedded in said aromatic foam glass as described in this invention.

Mosquito repelling test was used in the studies reported in FIGS. 5A and 5B whereby the test generally comprising the following steps: (1) releasing 100 female mosquitoes (Culex quinquefasciatus), age 4-5 days, into a testing area, and closing door to allow mosquitoes to adapt to the environment; (2) sending 6 participants into the room to catch mosquitoes landed on participants by using capturing tubes in 10 minute time period; (3) counting number of mosquitoes caught and sending them back into the room; (4) resting for 10 minutes and sending same 6 participants into the room, but each occupying different spot each time; (5) following steps 2-4 for 3 more times; (6) terminating all mosquitoes in the room after completion of steps 1-5; (7) placing one type of mosquito repelling samples into the room and repeat the steps 1-6. In the studies, there were three different types of mosquito repelling samples, namely foam glass samples infused with citronella oil mixture (AFG), citronella oil mixture solution, and 100% pure citronella oil. The final mosquito repelling rate (%) was calculated by the following formula:

Repelling rate = ((# of mosquitoes caught by participants in room without samples - # of mosquitoes caught by participants in room with samples/ # of mosquitoes caught by participants in room without samples)* 100)

The results as indicated in FIGS. 5A and 5B have suggested that mosquito (Culex quinquefasciatus) repelling efficiency rate of foam glass samples infused with citronella oil mixture (AFG) as described in this invention is significantly higher than the repelling rates of subjected areas with no presence of AFG as well as citronella oil mixture solution, and 100% pure citronella oil.

Claims

1. An aromatic foam glass comprising: a body wherein said body comprises adhered glass particles; a plurality of pores formed within said body wherein each of said plurality of pores has a size in a range substantially between 0.1 mm and 2.0 mm; and an essential oil mixture wherein said essential oil mixture is infused into said body of the aromatic foam glass.

2. The aromatic foam glass according to claim 1 wherein said body has a bulk density of between 0.19 g/cm³ and 0.4 g/cm³ and a porosity of between 85% and 91%.

3. The aromatic foam glass according to claim 1 wherein sizes of said glass particles are no more than 75 microns.

4. The aromatic foam glass according to claim 1 wherein said glass particles comprises crushed waste glass.

5 The aromatic foam glass according to claim 1 wherein said plurality of pores are distributed randomly throughout said body.

6. The aromatic foam glass according to claim 1 wherein said plurality of pores are formed homogenously throughout said body.

7. The aromatic foam glass according to claim 1 wherein said essential oil mixture comprising 1% to 4% by weight of a gel wax, 20% to 35% by weight of an essential oil, 10% to 15% by weight of polyethylene glycol (PEG), 7% to 10% by weight of distillates, and 45% to 55% by weight of ethanol based on the total weight of said essential oil mixture.

8. The aromatic foam glass according to claim 7 wherein the essential oil is selected from a group consisting one or more of: citronella oil, lemongrass oil, citrus oil, orange oil, eucalyptus oil, tea tree oil, kaffir lime leaf oil, lavender oil, vetiver oil, basil oil, thyme oil, menthol oil and peppermint oil.

9. The aromatic foam glass according to claim 1 wherein said essential oil mixture is a citronella oil mixture with pest resistant properties comprising 2% to 4% by weight of the gel wax, 20% to 35% by weight of the citronella oil, 10% to 12% by weight of polyethylene glycol (PEG), 7% to 10% by weight of the distillates, and 48% to 55% by weight of ethanol based on the total weight of said citronella oil mixture.

10. The aromatic foam glass according to claim 7 or 9 wherein said polyethylene glycol is consisted of 2% to 4% of polyethylene glycol at molecular weight of 35000 and 6% to 8% of polyethylene glycol at molecular weight of 1450.

11. A method of producing an aromatic foam glass, wherein said aromatic foam glass comprising a body, a plurality of pores, and an essential oil mixture embedded in the body, comprising the steps of:

- crushing glass particles with an industrial edge runner and selecting said glass particles of no more than 75 microns by a vibrating sieve",

- combining 80% to 90% by weight of said glass particles with 1 % to 2 % by weight of a foaming agent, and 9% to 12% by weight of an additive based on the total weight of a glass mixture sample;

- letting the sample cool down at room temperature for at least 10 hours in a furnace;

- cutting cooled sample into size and shape as required;

- placing said container in a vacuum chamber and conducting vacuuming at pressure of below 0.1 bar for 15-60 minutes at room temperature.

12. The method of claim 1 1 wherein said additive is selected from fluxing agent, colorant, strengthener or binding agent.

13. The method of claim 1 1 or 12 wherein said fluxing agent is selected from iron oxide (Fe203), sodium hydroxide (NaOH), sodium oxide (Na20), potassium oxide (K20), calcium oxide (CaO), Magnesium oxide (MgO), boron oxide (B203), cerium oxide (Ce02), sodium borate (Na2B407) and sodium hydrogen phosphate (Na2HP04).

14. The method of claim 11 or 12 wherein said colorant is selected from iron oxide (Fe203), cobalt oxide (Co304), copper oxide (CuO), copper(II)oxide (Cu20), copper sulfate (CuS04), manganese oxide (Mn02), chromium oxide (Cr203),and zinc oxide (ZnO).

15. The method of claim 1 1 or 12 wherein said strengthener is selected from silicon carbide (SiC), titanium oxide (Ti02), boron oxide (B203), aluminum oxide (A1203), sodium borate

(Na2B407), sodium hydrogen phosphate (Na2HP04) and boric acid (H2B03).

16. The method of claim 1 1 or 12 wherein said binding agent is selected from sodium silicate solution (Na2Si307) and kaolin clay.

17. The method of claim 1 1 wherein each of said plurality of pores has a size in a range substantially between 0.1 mm and 2.0 mm.

18. The method of claim 1 1 wherein said body has a bulk density of between 0.19 g/cm³ and 0.4 g/cm³ and a porosity of between 85% and 91%.

19. The method of claim 1 1 wherein said essential oil mixture comprising 1% to 4% by weight of a gel wax, 20% to 35% by weight of an essential oil, 10% to 15% by weight of polyethylene glycol (PEG), 7% to 10% by weight of a distillate, and 45% to 55% by weight of ethanol based on the total weight of said essential oil mixture.

20. The method of claim 19 wherein the essential oil is selected from a group consisting one or more of: citronella oil, lemongrass oil, citrus oil, orange oil, eucalyptus oil, tea tree oil, kaffir lime leaf oil, lavender oil, vetiver oil, basil oil, thyme oil, menthol oil and peppermint oil.

21. The method of claim 1 1 wherein said essential oil mixture is a citronella oil mixture with pest resistant properties comprising 2% to 4% by weight of the gel wax, 20% to 35% by weight of the citronella oil, 10% to 12% by weight of polyethylene glycol (PEG), 7% to 10% by weight of the distillate, and 48%) to 55% by weight of ethanol based on the total weight of said citronella oil mixture.

22. The method of claim 19 or 21 wherein said polyethylene glycol is consisted of 2% to 4% of polyethylene glycol at molecular weight of 35000 and 6% to 8% of polyethylene glycol at molecular weight of 1450.