Manufacturing method for freshness-preserving packaging material

Abstract

To provide a functional coating which has a high effect of adsorbing various odors in a space where sufficient ultraviolet rays do not reach and further has a decomposition function by making the coating contain visible light-responsive photocatalyst powder as well as an adsorbent.SOLUTION: Provided is a functional coating 13 containing visible light-responsive photocatalyst powder. The functional coating is made to contain as an adsorbent at least one of sludge generated in a water purification plant, dried powder of dewatered sludge obtained by subjecting sludge accumulated in the river or lake to a dewatering treatment, and pulverized powder of plants obtained by mixing leaves and stems of plants.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a freshness-preserving packaging material coated with a functional paint containing a visible light responsive photocatalyst powder. [Background technology]

[0002] For example, Patent Document 1 proposes an apatite that exhibits photocatalytic function even under visible light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2005 / 110598 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] The apatite proposed in Patent Document 1 exhibits photocatalytic function even under visible light, making it possible to use the material in spaces such as indoors where ultraviolet light has difficulty reaching. However, in closed spaces such as indoors or in packaging materials for fruit, unlike outdoors, odors and ethylene gas may remain, depending on the situation, so high photocatalytic capabilities are required. However, photocatalysts that use visible light do not have a higher catalytic function than photocatalysts that use ultraviolet light.

[0005] Therefore, the present invention aims to provide a freshness-preserving packaging material that has a high odor absorption effect in spaces where ultraviolet light does not reach sufficiently by incorporating an adsorbent together with a visible light responsive photocatalyst powder, and that has a functional paint with decomposition function to suppress, absorb, and decompose ethylene gas. [Means for solving the problem]

[0006] The functional coating material 13 of the present invention described in claim 1 is a method for producing a freshness-preserving packaging material 30 by applying a functional coating material 13 containing a visible light responsive photocatalyst powder, the functional coating material 13 containing a dehydrated sludge dried powder obtained by dehydrating sludge generated in a water purification plant and a finely ground plant powder obtained by mixing leaves and stems of herbaceous plants as adsorbents, and the visible light responsive photocatalyst powder contains at least one metal atom A selected from the group consisting of Ca, Al, La, Mg, Sr, Ba, Pb, Cd, Eu, Y, Ce, Na, and K. and at least one metal atom B selected from the group consisting of Ti, Zr, and W, and at least one metal atom C selected from the group consisting of Cr, Co, Cu, Fe, and Ni. The dewatered sludge dried powder is prepared by mixing solid particles of the same type of sludge as the deposited sludge generated in the water purification plant that supplies tap water with the deposited sludge to generate spaces in the sludge, performing solid-liquid separation by its own weight depending on the moisture content, heating and drying with microwaves to a moisture content of 25% to 50%, and then natural drying to reduce the moisture content to 25% to 50%. 15%~20% and then calcining the mixture at a temperature of 400° C. or less. plants The freshness-preserving packaging material 30 is obtained by mixing and gelling the leaves and stems of the plant, and then drying them, and is characterized in that the freshness-preserving packaging material 30 has a packaging body 30A that contains the contents and has at least one side as an opening 32, a lid 30B that covers at least the opening 32, and a transparent film 30C that covers the opening 32, and the functional paint 13 containing the visible light responsive photocatalyst powder, the dehydrated sludge dried matter powder, and the finely ground plant powder is applied to the packaging inner surface 31 of the packaging body 30A. The present invention described in claim 2 is characterized in that, in the manufacturing method of the freshness-preserving packaging material 30 described in claim 1, the functional paint 13 further contains calcium hydroxide powder obtained by hydrating and pulverizing seashells or chicken egg shells that have been fired at high temperatures. The present invention as set forth in claim 3 is characterized in that in the method for producing freshness-preserving packaging material 30 as set forth in claim 1 or 2, the functional paint 13 further contains silver particles. The present invention as set forth in claim 4 is a method for producing a freshness-preserving packaging material 30 as set forth in any one of claims 1 to 3, further comprising the step of adding to the functional paint 13 finely pulverized powder of deep-sea rocks obtained by crushing rocks formed by solidifying and accumulating floating matter in the sea, and the finely pulverized powder of deep-sea rocks is SiO 2 , MgO, CaO, and CO 2 + (H 2 O±) is characterized in that the total content of the components is 50% or more of the total components. Effect of the Invention

[0007] According to the freshness-preserving packaging material of the present invention, a functional paint containing a dehydrated sludge dried material powder that adsorbs ammonia, acetic acid, formaldehyde, toilet odors, cigarette odors, and pet odors, and a finely ground plant powder that has the effect of suppressing and adsorbing ethylene gas in particular, together with a visible light responsive photocatalyst powder as an adsorbent is applied to the inner surface of the packaging material that contains the contents, such as fresh flowers or fruits and vegetables.Since the functional paint has the effect of suppressing and adsorbing ethylene gas generated from the contents, the freshness of the contents can be preserved and various odors can be adsorbed and decomposed in spaces where ultraviolet light does not reach sufficiently. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 shows a substrate coated with a functional coating material according to an embodiment of the present invention. [Diagram 2] FIG. 1 shows a freshness-preserving packaging material coated with a functional paint according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The manufacturing method of the freshness-preserving packaging material according to the first embodiment is to incorporate dehydrated sludge dried powder obtained by dehydrating sludge produced in a water purification plant, and finely ground plant powder obtained by mixing leaves and stems of herbaceous plants, as adsorbents, into a functional paint, and use apatite containing at least one metal atom A selected from the group consisting of Ca, Al, La, Mg, Sr, Ba, Pb, Cd, Eu, Y, Ce, Na, and K, at least one metal atom B selected from the group consisting of Ti, Zr, and W, and at least one metal atom C selected from the group consisting of Cr, Co, Cu, Fe, and Ni, as the visible light responsive photocatalyst powder, and the dehydrated sludge dried powder is prepared by mixing solid particles of the same type of sludge as the deposited sludge produced in a water purification plant that supplies tap water, generating spaces in the sludge, performing solid-liquid separation by its own weight according to the moisture content, heating and drying with microwaves to make the moisture content 25% to 50%, and then natural drying to make the moisture content 25% to 50%. 15%~20% and further calcining at a temperature of 400°C or less, and the finely ground plant powder is obtained by mixing and gelling the leaves and stems of herbaceous plants, and then drying them, and the freshness-preserving packaging material has a packaging body that contains the contents and has at least one side as an opening, a lid that covers at least the opening, and a transparent film that covers the opening, and a functional paint containing a visible light responsive photocatalyst powder, a dehydrated sludge dried matter powder, and a finely ground plant powder is applied to the inner surface of the packaging body. According to this embodiment, the dehydrated sludge dried matter powder that adsorbs ammonia, acetic acid, formaldehyde, toilet odor, tobacco odor, and pet odor, and the finely ground plant powder that has an effect of suppressing and adsorbing ethylene gas in particular are contained as an adsorbent together with the visible light responsive photocatalyst powder, so that the functional paint according to this embodiment can adsorb and decompose various odors in a space where ultraviolet light does not reach sufficiently. Furthermore, according to this embodiment, when the lid is removed from the main packaging body to expose the contents, for example when the contents are displayed and sold in a store, the ethylene generated from the contents is adsorbed and decomposed, thereby maintaining the freshness of the contents.

[0010] The second embodiment of the present invention is a method for producing a freshness-preserving packaging material according to the first embodiment, in which the functional paint further contains calcium hydroxide powder obtained by hydrating and pulverizing shells or egg shells that have been calcined at high temperatures. According to this embodiment, the antibacterial effect can be further improved.

[0011] The third embodiment of the present invention is a method for producing a freshness-preserving packaging material according to the first or second embodiment, in which silver particles are further contained in the functional paint. According to this embodiment, it is possible to further enhance the antibacterial and deodorizing effects, the antioxidant effects due to oxygen removal, and the prevention of oxidative deterioration.

[0012] The fourth embodiment of the present invention is a method for producing a freshness-preserving packaging material according to the first to third embodiments, further comprising adding to the functional paint a finely pulverized powder of deep sea rocks, which are formed by crushing rocks formed by solidifying and depositing floating matter in the sea, and the finely pulverized powder of deep sea rocks is SiO 2 , MgO, CaO, and CO 2 + (H 2 O±) is 50% or more of the total components. By using the functional coating material according to this embodiment, various odorous components in spaces where ultraviolet light does not reach sufficiently can be further reduced, and active oxygen can be reduced by the antioxidant effect. EXAMPLES

[0013] An embodiment of the functional paint according to the present invention will now be described. The functional coating material according to this embodiment contains a visible light responsive photocatalyst powder. As the visible light responsive photocatalyst, a copper-based compound modified tungsten oxide photocatalyst, a copper-based compound modified titanium oxide photocatalyst, or an iron-based compound modified titanium oxide photocatalyst can be used. In addition, it is preferable to use apatite that absorbs ultraviolet light and visible light, as disclosed in Patent Document 1, as the visible light responsive photocatalyst. This apatite contains metal atom A, metal atom B, and metal atom C. Metal atom A is a metal atom contained in normal apatite, metal atom B is a metal atom that absorbs ultraviolet light, and metal atom C is a metal atom that absorbs visible light. In this way, by including metal atoms that absorb visible light as well as those that absorb ultraviolet light in the metal atoms contained in the apatite, the photocatalytic function can be exerted not only by ultraviolet light but also by visible light. Also, by attaching Fe or carbon to the surface of this apatite powder, the wavelength range of light absorbed appears in the visible light range compared to apatite without the attachment, and the absorption of visible light is enhanced.

[0014] The metal atom A is at least one metal atom selected from the group consisting of Ca, Al, La, Mg, Sr, Ba, Pb, Cd, Eu, Y, Ce, Na, and K, and is the main component of the metal atoms contained in apatite. Among these, Ca is the most common. The metal atom B that absorbs ultraviolet light is at least one metal atom selected from the group consisting of Ti, Zr, and W. Among these, Ti is most preferred. The content of the metal atom B is preferably 3 mol% to 11 mol%, more preferably 8 mol% to 10 mol%, based on the total metal atoms contained in the apatite. The metal atom C that absorbs visible light is at least one metal atom selected from the group consisting of Cr, Co, Cu, Fe, and Ni. Of these, Cr is most preferred. The content of the metal atom C is preferably 0.5 mol% to 2 mol%, more preferably 0.5 mol% to 1.5 mol%, based on the total metal atoms contained in the apatite. In this apatite, it is preferable that metal atoms A constitute the apatite crystal structure, and that metal atoms A are partly substituted with metal atoms B and C.

[0015] The functional coating material according to this embodiment contains at least one of a powder of dried dewatered sludge and a powder of finely ground plant material as an adsorbent. The dried dewatered sludge powder is made by dewatering sludge produced in water purification plants and sludge accumulated in rivers, lakes and marshes. The dewatered sludge dried powder can be obtained, for example, by the following method. The sedimentary sludge generated in water purification plants that supply tap water is mixed with solid particles of the same type of sludge as the sedimentary sludge, creating spaces within the sludge, and solid-liquid separation is performed using the weight of the sludge depending on the moisture content, after which it is heated and dried using microwaves.In other words, when microwaves reach the inside of the sludge, the moisture inside the particle masses heats up, and the moisture evaporates from the spaces created by the mixing of the solid particles, allowing for uniform drying. After drying, calcium oxide (CaO) or calcium hydroxide (Ca(OH) 2 ) may be mixed. After drying, a clay mineral may be added. Zeolite or bentonite may be used as the clay mineral. Also, iron oxide, aluminum chloride, and aluminum oxide may be mixed in. Since aluminum chloride and aluminum oxide are used as coagulants to coagulate the sludge in water purification plants, the amount of these to be mixed is adjusted taking into account the amount of aluminum already contained in the sludge. Microwave drying reduces the moisture content to 25% to 50%, and then natural drying reduces the moisture content to about 15% to 20%. The material is then dried at a temperature of 100°C or less for 30 to 120 minutes, and then fired at a temperature of 400°C or less. This firing process allows the formation of numerous pores. Such powdered dried dewatered sludge has a physical adsorption capacity due to the voids and a chemical adsorption capacity due to the surface hydroxyl groups, and adsorbs ammonia, acetic acid, formaldehyde, toilet odors, cigarette odors, and pet odors. By incorporating this powder of dried dewatered sludge into functional paint, it has both physical and chemical adsorption power, and therefore exerts a high adsorption function.

[0016] The finely ground plant powder is made from tomatoes, kenaf, etc. plants The gel is obtained by mixing and gelling the leaves and stems of the plant, and then drying the gel, and the average diameter is preferably 50 μm to 300 μm. The finely ground plant powder has a particular inhibitory and adsorbent effect on ethylene gas.

[0017] By using a functional paint containing dehydrated sludge dried powder and finely ground plant powder together with a visible light responsive photocatalyst powder as an adsorbent, it is possible to adsorb and decompose various odors in spaces where ultraviolet light does not reach sufficiently.

[0018] Moreover, the functional coating material according to this embodiment preferably further contains calcium hydroxide powder obtained by hydrating and pulverizing seashells or eggshells that have been calcined at high temperatures. The calcium hydroxide powder preferably has an average particle size of 3.5 μm to 300 μm and a pH of 12 to 13. As the shells, scallop shells are suitable, but abalone shells, turban shells, surf clam shells, sea urchin shells or coral can also be used. Seashells or eggshells are washed to remove foreign matter, and baked in a rotary kiln at a furnace temperature of about 500°C for 40 to 60 minutes. When eggshells are used, the protein skin attached to the inside of the shell is removed before baking. The baked seashells are crushed to an average particle size of about 30 mm after removing any attached matter. The baked eggshells are crushed to an average particle size of about 5 to 10 mm after removing any attached matter. The crushed seashell powder or eggshell powder is further baked again at 900°C to 1000°C for 40 to 90 minutes. After baking, the calcium hydroxide powder is hydrated and pulverized to an average particle size of 3.5 μm to 300 μm, more preferably 20 μm to 50 μm, and pH 12 to 13. By further adding calcium hydroxide powder to the functional coating material, the antibacterial effect can be further enhanced.

[0019] Moreover, the functional paste according to this embodiment preferably further contains silver particles. The silver particles have an average particle size of 0.001 μm to 0.05 μm, more preferably 0.001 μm to 0.005 μm, and are dispersed in an aqueous solution. Silver particles with an average particle size of 0.001 μm to 0.005 μm are nanosilver. The silver particles are attached to a photocatalyst powder (titanium apatite powder that absorbs ultraviolet and visible light). By attaching the silver particles to the surface of the titanium apatite powder, the silver can be dispersed and the antibacterial and deodorizing effects of silver, as well as antioxidant effects by removing oxygen, and anti-oxidative deterioration effects are easily exhibited. By further incorporating silver particles into the functional paint, the antibacterial and deodorizing effects can be further enhanced.

[0020] In addition, it is preferable that the functional coating material according to this embodiment further contains finely pulverized powder of deep sea rocks, which are crushed rocks formed when floating matter in the sea solidified and accumulated in a layer. The finely ground powder of deep ocean rock is SiO 2 , MgO, CaO, and CO 2 + (H 2 O±) constitutes more than 50% of the total components. For example, SiO 2 (22.14%), TiO 2 (0.68%), Al 2 O 3 (4.62%), FeO (3.38%), MnO (0.08%), MgO (13.92%), CaO (20.89%), Na 2 O(0.28%), K 2 O (2.71%), P 2 O 5 (0.14%), and CO 2 + (H 2 O±) (31.15%) of deep-sea stones (Aqua PS manufactured by Estate.com Ltd.). By further adding finely ground powder of deep sea rocks to the functional paint, odorous components can be further reduced and active oxygen can be reduced through the antioxidant effect.

[0021] In addition, the functional coating material according to this embodiment preferably further contains a clay mineral such as zeolite or bentonite. The clay mineral is preferably a porous clay mineral mainly composed of at least one selected from sepiolite, smectite, imogolite, palygorskite, kaolin, montmorillonite, zeolite, bentonite, attapulgite, acid clay, and limonite, and mudstone or activated carbon can also be used. By mixing the clay mineral, granulation can be achieved, and the clay mineral forms a porous structure, thereby exerting an ethylene gas adsorption effect. It is also preferable to further include a carbonized powder made from a plant. The carbonized powder may be made from a plant such as tomato or kenaf. plants It is preferable to use the leaves and stems of The average diameter of the carbide powder is preferably 50 μm to 300 μm. By using calcium hydroxide powder with an average particle size of 3.5 μm to 300 μm, silver particles with an average particle size of 0.001 μm to 0.05 μm, finely ground plant powder with an average diameter of 50 μm to 300 μm, and carbide powder with an average diameter of 50 μm to 300 μm, it is possible to achieve an antibacterial effect by the calcium hydroxide powder, an antibacterial and deodorizing effect by the silver particles, an ethylene gas suppression and adsorption effect by the finely ground plant powder, and an ethylene gas adsorption effect by the carbide powder. It is also preferable that the composition further contains manganese peroxide, which can enhance the suppression effect against ethylene gas generated by bananas in particular.

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a substrate coated with the functional paint of this embodiment, where FIG. 1(a) shows the substrate before it is attached to a wall surface, and FIG. 1(b) shows the substrate after it has been attached to the wall surface. The functional coating material 13 of this embodiment contains powder of dried dehydrated sludge as an adsorbent. The substrate 10 is wallpaper having one surface 11 on which a pattern or design is printed and the other surface 12 which is attached to a wall surface 20, with functional paint 13 applied to the back surface 12. The substrate 10 may be made of pulp made of plant fibers, or may be made of wood or resin. The substrate 10 is attached to a wall surface 20 using an adhesive. The substrate 10 is permeable to visible light and odorous gases. Therefore, the functional paint 13, which is applied to the wall surface 20 side, can adsorb and decompose various odors. Furthermore, since the functional paint 13 is not applied to the surface 11 of the base material 10, patterns and designs can be printed thereon. In this embodiment, the wall surface 20 includes the ceiling surface. In this way, by applying functional paint 13 to the back surface 12 of the substrate 10 of this embodiment, patterns and designs can be printed on the front surface 11, and the substrate 10 can adsorb and decompose various odors in the indoor space to which it is attached.

[0023] FIG. 2 is a diagram showing a freshness-preserving packaging material coated with the functional coating material of this embodiment. The functional paint 13 of this embodiment contains finely ground plant powder as an adsorbent. The freshness-preserving packaging material 30 contains items such as fresh flowers, fruits and vegetables, fresh fish, processed foods, or grains. The freshness-preserving packaging material 30 has a functional paint 13 applied to the inner surface 31 of the packaging material that contains the contents. More specifically, the freshness-preserving packaging material 30 has a packaging body 30A that contains the contents and has at least one side as an opening 32, a lid body 30B that covers at least the opening 32, and a transparent film 30C that covers the opening 32. The inner surface 31 of the packaging body 30A is composed of an inner bottom surface 31a and an inner side surface 31b, and the functional paint 13 is applied to the inner bottom surface 31a and the inner side surface 31b. According to this embodiment, when the lid body 30B is removed from the packaging body 30A to make the contents visible, for example when the contents are displayed and sold in a store, the functional paint 13 is applied to the inner surface 31 of the packaging material, so that the ethylene generated from the contents is adsorbed and decomposed, thereby maintaining the freshness of the contents. In this embodiment, the functional paint 13 is applied to the inner surface 31 of the packaging material that contains the contents, but it may also be applied to the outer surface of the packaging material, and if the packaging material has multiple layers, the functional paint 13 may be applied to the middle layer. [Industrial Applicability]

[0024] According to the present invention, a method for producing a freshness-preserving packaging material coated with a functional paint capable of adsorbing and decomposing odors, particularly in closed spaces where ultraviolet light has difficulty reaching, can be provided. [Explanation of symbols]

[0025] 10 Base material 11 Surface 12 Back side 13 Functional paint 20 Wall 30 Freshness-preserving packaging materials 30A packaging material body 30B Lid body 30C Transparent Film 31 Inner surface of packaging material 31a Inner bottom surface 31b Inside surface 32 Opening

Claims

1. A method for producing a freshness-preserving packaging material by applying a functional paint containing a visible light responsive photocatalyst powder, The functional paint contains, as adsorbents, a dehydrated sludge dried powder obtained by dehydrating sludge produced at a water purification plant and a finely ground plant powder obtained by mixing leaves and stems of herbaceous plants; As the visible light responsive photocatalyst powder, At least one metal atom A selected from the group consisting of Ca, Al, La, Mg, Sr, Ba, Pb, Cd, Eu, Y, Ce, Na, and K; At least one metal atom B selected from the group consisting of Ti, Zr, and W; At least one metal atom C selected from the group consisting of Cr, Co, Cu, Fe, and Ni; Using an apatite containing The dehydrated sludge dried powder is Mixing solid particles of the same kind of sludge as the sedimentary sludge generated at the water purification plant that supplies tap water with the sedimentary sludge to create spaces in the sludge; Solid-liquid separation is carried out according to the water content. Heat and dry with microwaves to reduce the moisture content to 25% to 50%. Then, the moisture content is reduced to 15% to 20% by natural drying. Furthermore, it is obtained by firing at a temperature of 400° C. or less, The finely ground plant powder is The leaves and stems of the herbaceous plant are mixed and gelled, and then dried to obtain a gel; The freshness-preserving packaging material is A packaging body that contains an item to be contained and has at least one surface that has an opening; A cover body that covers at least the opening; A transparent film covering the opening; having The functional coating material containing the visible light responsive photocatalyst powder, the dehydrated sludge dried matter powder, and the finely pulverized plant powder is applied to the inner surface of the packaging body. A method for producing a freshness-preserving packaging material comprising the steps of:

2. The functional paint further contains calcium hydroxide powder obtained by hydrating and pulverizing shells or egg shells that have been fired at high temperatures. A method for producing the freshness-preserving packaging material according to claim 1.

3. The functional paint further contains silver particles. A method for producing the freshness-preserving packaging material according to claim 1 or 2.

4. The functional coating material further contains finely ground powder of deep ocean rocks, which are crushed rocks formed by solidifying and depositing floating matter in the sea, The finely pulverized powder of deep sea rock is SiO ２ , MgO, CaO, and CO ２ ＋ (H ２ The total amount of the components (O±) is 50% or more of the total amount of the components. A method for producing the freshness-preserving packaging material according to any one of claims 1 to 3.

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