A method for preparing luminous soil covering material using tree waste

Abstract

The present invention belongs to the field of landscaping technology and discloses a method for preparing luminous soil covering materials using tree waste. The method comprises the following steps: (1) crushing wood or branch waste; (2) adding a low-crystalline transparent polymer solution to molten wax, and then adding luminous material particles to obtain a suspension A; (3) mixing a dispersant and a salt aqueous solution, and then adding the suspension A from step (2) to form a suspension B; (4) adding the particles obtained in step (1) to the suspension B prepared in step (3), stirring, separating, washing, and drying to obtain soil covering particles with luminous function. The luminous particles obtained in the present invention have a long lifespan, are not easily washed away by rainwater, and have good luminous properties.

Description

Technical Field

[0001] The invention belongs to the technical field of gardening and greening, and in particular relates to a method for preparing luminous soil covering material by utilizing tree waste. Background Art

[0002] Regular pruning of urban greening trees generates a significant amount of branch waste. Currently, this waste is mostly utilized through composting, biomass fuel production, or direct fuel use. However, the resource utilization quality is low, and the added value of the recycled products is relatively low. Using soil cover material produced from this waste to cover exposed urban surfaces would not only effectively control dust pollution, but also return the organic matter in the branches to the soil, increasing soil fertility. It would also reduce carbon dioxide emissions from waste incineration.

[0003] The published paper "Research and Application of Transforming Green Cover from Greening Waste" (Green Environmental Protection Building Materials, Issue 12, 2019, pp. 248-249, Ma Yuxiang, Qin Fei, Li Bowen, Song Wei, and Liu Pan) reports that tree branches are crushed, sterilized, and dried, and then flame retardants, pigments, polymer binders, etc. are added to mix and molded into soil cover materials of various shapes. Chinese invention patent publication CN105557406A discloses a method for producing organic cover from gardening waste. The raw material is gardening waste generated during maintenance and planting. The raw material is mechanically crushed to a fragment size of no more than 5 cm. After mechanical crushing, the lignin and bark in the fragments are enzymatically hydrolyzed. After spraying a phosphate flame retardant solution, wood dye is evenly sprayed on the gardening waste fragments to dye them. Finally, the fragments are sterilized, dried, and vacuum-packaged. This technology uses landscaping waste as raw material to create organic mulch, making more efficient use of resources. After pulverization, enzymatic hydrolysis, drying, flame retardant treatment, dyeing, and sterilization and insecticide treatment, the resulting organic mulch is fully disinfected, non-perishable, and hygienically packaged for easy storage. While the mulch material produced using this patented technology can cover the soil, prevent dust, and beautify the environment, it does not glow at night.

[0004] Currently, luminous materials are primarily endowed with this glow-in-the-dark feature through two main approaches. One approach involves adding a luminescent powder to the raw materials used in their production, followed by mixing and molding using the original processing techniques. For example, Chinese Patent Publication CN105670236A proposes a method for preparing luminous PET resin. This involves mixing a luminous colorant made from strontium aluminate luminescent powder with ethylene bisstearamide, polypropylene grafted with maleic anhydride, and PET. The mixture is then extruded and granulated in a twin-screw extruder. The resulting plastic granules can be used to manufacture various luminous plastic parts. Chinese Patent Publication CN106186827A discloses a castable luminous floor and its preparation method. Polyurethane, EVA, and luminous stone are mixed in appropriate proportions, mixed evenly in a drum mixer, and then cast into a luminous floor that glows at night. However, the luminous material produced by this technical solution only has a small amount of luminous powder on the surface that actually functions, while the majority of the luminous powder dispersed within the material does not contribute to the luminous effect. This results in high luminous powder consumption and costs. Another method for imparting luminous properties to materials is by bonding or coating them onto the surface of a material or component. For example, Chinese patent publication CN108467672A proposes a method for preparing a modified resin-based luminous coating. This method uses a polyurethane base material, homemade magnesium fluoride and fluorite powder as luminescent materials, a mixed colloid as a modifier, and anhydrous ethanol and ethylene glycol butyl ether as additives to produce the modified resin-based luminous coating. Any material or component coated with this coating can achieve luminous properties. Chinese patent publication CN111777332A describes a technical solution for preparing luminous ceramics. A luminous glaze, pre-prepared from luminous powder, surfactant, and glaze powder, is applied to an unglazed ceramic product that has been fired at high temperature for high-grade ceramic formation. After drying, the ceramic product is fired to produce the luminous ceramic. While this method can reduce the consumption of luminous powder, the luminous powder is susceptible to the effects of other chemical components and high temperatures during the preparation process, causing it to lose its luminous properties. In addition, the following problems still exist in the existing technical solutions for preparing wood chip particles from waste wood or branches:

[0005] (1) The wood chips or particles obtained by crushing are of different sizes and shapes and have a rough surface. If a coating containing luminous powder is used, it is difficult to apply a layer of coating evenly on the surface using general coating or bonding methods.

[0006] (2) During the coating process, after the coating forms a film, it is easy to cause the wood chips and particles to stick together instead of being dispersed wood chips and particles.

[0007] (3) Coat with luminous paint. After the paint forms a film, the waterproof coating will completely wrap the wood chips. When it encounters rain, the wood chips will float on the water surface and can be easily washed away.

[0008] (4) The method of using a binder to bond the luminous powder to the surface of the wood particles. Due to the small size of the luminous powder particles and the irregular surface of the wood chips, the luminous powder is easily accumulated on the surface of the wood chips, and it is impossible to obtain a covering material with uniform luminous powder coverage.

[0009] (5) If the luminous powder is used directly without being processed, it will easily be soaked in water and lose its luminous properties during use. Summary of the Invention

[0010] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing luminous soil covering material using wood waste.

[0011] The purpose of the present invention is achieved through the following solutions:

[0012] A method for preparing a luminous soil covering material using tree waste comprises the following steps:

[0013] (1) crushing wood or branch waste to obtain wood or branch waste particles;

[0014] (2) dissolving a low-crystalline transparent polymer in an organic solvent to obtain a polymer solution, adding the polymer solution to molten wax, then adding luminescent material particles, and stirring to obtain a suspension A in which the luminescent material particles are dispersed;

[0015] (3) mixing the dispersant and the salt aqueous solution, adding the suspension A from step (2), and stirring to form a suspension B;

[0016] (4) Adding the particles obtained in step (1) to the suspension B prepared in step (3), stirring, separating, washing, and drying, to obtain soil covering particles with luminous function.

[0017] The pulverization in step (1) is to pulverize the wood or branch waste into particles with a size range of 0.5 to 2 cm.

[0018] The low-crystalline transparent polymer in step (2) is at least one of polystyrene (PS), butadiene-styrene diblock copolymer (SB), butadiene-styrene triblock copolymer (SBS), and ethylene-vinyl acetate copolymer (EVA). The polymer is added to improve the light transmission effect of the wax coating and enhance the bonding performance between the wax and the surface of the wood or branch waste particles.

[0019] The organic solvent in step (2) is at least one of toluene, xylene, ethyl acetate, ethylene dichloride, ethylene dichloride, d-limonene, and dipentene, preferably d-limonene, a non-toxic and harmless natural solvent.

[0020] The wax in step (2) has a melting point of 50 to 100° C. and includes at least one of paraffin wax, polyethylene wax, Fischer-Tropsch wax, and polypropylene wax; the molten wax is a wax heated to a temperature at or above its melting point.

[0021] The particle size of the luminous material particles in step (2) is in the range of 10 to 100 μm. It is a non-toxic, non-radioactive light-storing luminous material that can absorb sunlight or light during the day and store it in the material, and then convert the stored energy into light and release it at night or in a dark environment. It is at least one of the sulfide / sulfur oxide system, aluminate system, and silicate system luminous materials, preferably a strontium aluminate type luminous material or a rare earth strontium aluminate type luminous material.

[0022] The mass percentage of the low-crystalline transparent polymer in the polymer solution of step (2) is 1 to 5%.

[0023] The mass ratio of the wax, polymer solution and luminous material particles in step (2) is 100:1~10:0.1~1.

[0024] The stirring conditions in step (2) are: stirring at a speed of 500 to 1000 r / min at 50 to 100° C. for 30 to 60 minutes.

[0025] The dispersant in step (3) has a hydrophilic group at one end of the molecule and a lipophilic group at the other end, and includes at least one of stearic acid, polyethylene glycol ether, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0026] The salt aqueous solution in step (3) is an aqueous solution of one of sodium bromide, potassium bromide, magnesium bromide, calcium bromide, ammonium bromide, and zinc bromide; and the density of the salt aqueous solution is in the range of 1.3 to 1.6 g / mL.

[0027] The mass ratio of the salt aqueous solution, dispersant and suspension A in step (3) is 100:0.1-1:1-20.

[0028] The mixing temperature in step (3) is 50-100° C.; the stirring speed is 1000-5000 r / min; and the stirring time is 30-60 min.

[0029] The mass ratio of the particles in step (4) to suspension B is 1 to 10:100.

[0030] The stirring in step (4) is specifically as follows: the temperature is controlled to be 1-5°C lower than the melting temperature of the wax during stirring, stirring at a speed of 10-100 r / min for 10-30 minutes, then the temperature is lowered to room temperature, and stirring is continued for 20-30 minutes.

[0031] The washing in step (4) is to wash the particles 1 to 2 times with clean water at room temperature.

[0032] The mechanism of the present invention is:

[0033] Luminescent materials store light energy during the day and then emit it again at night. This method involves crushing pruned branches from urban greening trees into small particles of a predetermined size. The particles are then loaded with the luminescent material to create a nighttime luminescent covering material that can be used on exposed soil in places like hotels, public recreational areas, and home potted plants. This material prevents soil erosion, reduces dust, beautifies cities, and enhances nighttime landscapes.

[0034] The luminous covering material prepared by the present invention is pre-coated with a low-molecular-weight wax and then bonded to the surface of the particles. This effectively prevents the luminous material from being degraded by harmful factors such as water immersion, bioerosion, air oxidation, and loss, thereby extending the service life of the luminous material. Furthermore, since the luminous material is bonded to the surface of the particles in a granular form, the properties of the particles as a garden covering material are not affected.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] (1) The present invention uses low-molecular wax to wrap the luminescent material and then loads it on the surface of the particles, which reduces the amount of luminescent material used and reduces the cost. In addition, the luminescent material particles are wrapped with low-molecular wax, which can effectively prevent the luminescent material from being ineffective due to water immersion, biological erosion, and air oxidation, thereby increasing the service life of the luminescent material.

[0037] (2) The present invention first prepares the luminous material into a suspension of wax-coated particles, and then adheres the particles to the surface of the particles at a suitable temperature. This does not completely cover the entire surface of the particles, but leaves gaps between the particles, which does not hinder the water absorption and air permeability of the particles after loading the luminous material. After rain, the particles can quickly absorb water and increase their density, making them less likely to be washed away by rainwater.

[0038] (3) The present invention can use natural and non-toxic d-limonene as a solvent to achieve the miscibility of the polymer with the low-molecular wax at a lower temperature. The natural solvent is derived from orange peel and tangerine peel, which is not only environmentally friendly and healthy, but also can emit an orange fragrance for a long time.

[0039] (4) The present invention uses a salt aqueous solution as a suspension dispersion liquid for the luminous material particles, which solves the problem that the luminous material particles are too large and heavy to form a stable suspension after being wrapped by wax. DETAILED DESCRIPTION

[0040] The present invention will be described in further detail below with reference to the Examples, but the embodiments of the present invention are not limited thereto. Where specific conditions are not specified in the Examples, conventional conditions or conditions recommended by the manufacturer were used. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0041] Unless otherwise specified, all reagents used in the examples can be purchased from the market.

[0042] Polystyrene plastic: purchased from Sinopec, with an average molecular weight of 150,000.

[0043] Ethylene-vinyl acetate copolymer (EVA): purchased from Zhongke (Guangdong) Refining and Chemical Co., Ltd., with an average molecular weight of 12,000.

[0044] Polyethylene wax: purchased from Guangdong Xinhuayue Co., Ltd., with an average molecular weight of 2000.

[0045] Fischer-Tropsch wax: purchased from Qingdao Sino Chemical Co., Ltd., with an average molecular weight of 800.

[0046] Paraffin wax: purchased from Guangdong Xinhuayue Co., Ltd., with an average molecular weight of 500.

[0047] Polyethylene glycol ether: purchased from Yangzi Petrochemical-BASF Co., Ltd., PEG400.

[0048] Alkylphenol polyoxyethylene ether: purchased from Hai'an Petrochemical Plant, Jiangsu Province, OP-15.

[0049] Strontium aluminate type luminous powder: purchased from Guangdong Yuantai Chemical Co., Ltd., with a purity of 99.5%.

[0050] Rare earth strontium aluminate type luminous powder: purchased from Shenzhen Yaodexing Technology Co., Ltd., with a purity of 99.5%.

[0051] Example 1

[0052] (1) The branches produced by pruning trees for urban road greening are crushed into particles with a size range of 0.5 to 2 cm.

[0053] (2) Dissolve 1 gram of polystyrene plastic in 99 grams of d-limonene to prepare a 1% polystyrene plastic solution; then take 100 grams of paraffin wax with a melting point of 50°C and heat it to 50°C. Add 1 gram of the 1% polystyrene solution and 0.1 gram of strontium aluminate type luminescent powder with a particle size of 10 μm while stirring. Stir at 50°C and 1000 rpm for 60 minutes to evenly disperse the luminescent particles in the molten paraffin wax.

[0054] (3) After mixing 0.1 g of stearic acid with 100 g of a sodium bromide aqueous solution with a density of 1.3 g / mL at 50° C., 10 g of a mixture of the luminous powder prepared in step (2) and molten paraffin was added at a stirring speed of 1000 rpm, and stirred for 30 min to prepare a suspension of luminous powder particles wrapped in paraffin;

[0055] (4) Take 100 g of the suspension prepared in step (3), cool it to 45° C., add 1 g of the particles prepared in step (1), stir at a speed of 10 rpm for 10 min, further reduce the temperature to room temperature, continue stirring for 20 min, filter to remove the suspension, add clean water and wash twice to remove the residual suspension and unadhered luminous material particles on the surface of the particles, and obtain a particle covering material loaded with luminous material-coated microspheres after drying.

[0056] It has been measured that every 1cm 2 The surface of the particles is loaded with 20 luminous particles, and the soil surface is covered with 2 cm thick particles of this embodiment. After 5 hours of sunlight exposure during the day, obvious afterglow can still be observed on the surface of the particles within 8 hours at night.

[0057] Example 2

[0058] (1) The branches produced by pruning trees for urban road greening are crushed into particles with a size of 0.5 to 2 cm.

[0059] (2) Dissolve 5 g of ethylene-vinyl acetate copolymer (EVA) in 95 g of d-limonene to prepare a 5% ethylene-vinyl acetate copolymer solution. Then, take 100 g of polyethylene wax with a melting point of 100°C and heat it to 100°C. Add 10 g of the 5% plastic solution and 1 g of strontium aluminate type luminescent powder with a particle size range of 100 μm while stirring. Stir at 100°C and 1000 r / min for 30 min to evenly disperse the luminescent particles in the molten polyethylene wax.

[0060] (3) After mixing 1 g of polyethylene glycol ether with 100 g of a calcium bromide aqueous solution with a density of 1.6 g / mL at 100° C., 20 g of the mixture of the luminous powder prepared in step (2) and molten polyethylene wax was added at a stirring speed of 5000 rpm, and stirred for 60 min to prepare a suspension of luminous powder particles coated with molten polyethylene wax;

[0061] (4) Take 100 g of the suspension prepared in step (3), cool it to 95° C., add 10 g of the particles prepared in step (1), stir at a speed of 50 rpm for 30 min, further reduce the temperature to room temperature, continue stirring for 30 min, filter to remove the suspension, add clean water to wash 1 to 2 times to remove the residual suspension and unadhered luminous material particles on the surface of the particles, and obtain a particle covering material loaded with luminous material-coated microspheres after drying.

[0062] It has been measured that every 1cm 2 The surface of the particles is loaded with 20 luminous particles, and the soil surface is covered with 2 cm thick particles of this embodiment. After 7 hours of sunlight exposure during the day, obvious afterglow can still be observed on the surface of the particles for 9 hours at night.

[0063] Example 3

[0064] (1) Crush the branch waste generated by pruning trees for urban road greening into particles with a size of 0.5 to 2 cm.

[0065] (2) Dissolve 1 gram of ethylene-vinyl acetate copolymer (EVA) plastic in 99 grams of ethyl acetate to prepare a 1% ethylene-vinyl acetate copolymer solution. Then, take 100 grams of Fischer-Tropsch wax with a melting point of 100°C and heat it to 100°C. While stirring, add 10 grams of the 1% EVA solution and 1 gram of rare earth strontium aluminate type luminescent powder with a particle size of 10 μm. Stir at 100°C and 500 r / min for 30 minutes to evenly disperse the luminescent particles in the molten Fischer-Tropsch wax.

[0066] (3) After mixing 0.1 g of alkylphenol polyoxyethylene ether with 100 g of an aqueous solution of magnesium bromide having a density of 1.3 g / mL at 100° C., 20 g of a mixture of the luminous powder and molten wax prepared in step (2) was added at a stirring speed of 1000 rpm, and stirred for 60 min to prepare a suspension of luminous powder particles coated with molten Fischer-Tropsch wax;

[0067] (4) Take 100 g of the suspension prepared in step (3), cool it to 95° C., add 10 g of the particles prepared in step (1), stir at a speed of 100 rpm for 10 min, further reduce the temperature to room temperature, continue stirring for 30 min, filter to remove the suspension, add clean water and wash twice to remove the residual suspension and unadhered luminous material particles on the surface of the particles, and obtain covered particles loaded with luminous material-coated microspheres after drying.

[0068] It has been measured that every 1cm 2 The particle surface is loaded with an average of 20 luminous particles, and the soil surface is covered with 2 cm thick particles of this embodiment. After 6 hours of sunlight exposure during the day, obvious afterglow can still be observed on the particle surface for 9 hours at night.

[0069] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing luminous soil covering material using tree waste, characterized in that The following steps are involved: (1) crushing wood or branch waste to obtain wood or branch waste particles; (2) dissolving a low-crystalline transparent polymer in an organic solvent to obtain a polymer solution, adding the polymer solution to molten wax, then adding luminous material particles, and stirring to obtain a suspension A in which the luminous material particles are dispersed; (3) Mixing the dispersant and the salt aqueous solution, adding the suspension A from step (2), and stirring to form suspension B; (4) adding the particles obtained in step (1) to the suspension B prepared in step (3), stirring, separating, washing, and drying to obtain soil covering particles with luminous function; The low-crystalline transparent polymer in step (2) is at least one of polystyrene, butadiene-styrene diblock copolymer, butadiene-styrene triblock copolymer, and ethylene-vinyl acetate copolymer; The aqueous salt solution in step (3) is an aqueous solution of one of sodium bromide, potassium bromide, magnesium bromide, calcium bromide, ammonium bromide and zinc bromide.

2. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The pulverization in step (1) is to pulverize the wood or branch waste into particles with a size range of 0.5 to 2 cm.

3. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The organic solvent in step (2) is at least one of toluene, xylene, ethyl acetate, ethylene dichloride, ethylene dichloride, d-limonene, and dipentene; The wax in step (2) has a melting point of 50-100°C and includes at least one of paraffin wax, polyethylene wax, Fischer-Tropsch wax, and polypropylene wax; the molten wax is a wax heated to a temperature at or above its melting point.

4. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The particle size of the luminous material particles in step (2) ranges from 10 to 100 μm; the luminous material is a light-storage type luminous material, including a strontium aluminate type luminous material or a rare earth strontium aluminate type luminous material.

5. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The mass percentage of the low-crystalline transparent polymer in the polymer solution of step (2) is 1-5%; In step (2), the mass ratio of the wax, polymer solution and luminous material particles is 100:1~10:0.1~1; The stirring conditions in step (2) are: stirring at a speed of 500-1000 r / min for 30-60 min at 50-100° C.

6. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The dispersant in step (3) includes at least one of stearic acid, polyethylene glycol ether, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether; The density of the aqueous salt solution in step (3) is in the range of 1.3 to 1.6 g / mL.

7. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The mass ratio of the salt aqueous solution, dispersant and suspension A in step (3) is 100:0.1~1:1~20.

8. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The mixing temperature in step (3) is 50-100° C.; the stirring speed is 1000-5000 r / min; and the stirring time is 30-60 min.

9. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The mass ratio of the particles in step (4) to suspension B is 1-10:

100.

10. The method for preparing luminous soil covering material using tree waste according to claim 1, characterized in that: The stirring in step (4) is specifically as follows: the temperature during stirring is controlled at 1-5°C lower than the melting temperature of the wax, stirring at a speed of 10-100 r / min for 10-30 minutes, then lowering the temperature to room temperature, and continuing stirring for 20-30 minutes; the washing in step (4) is washing the particles 1-2 times with clean water at room temperature.