Greening materials and methods

Abstract

To provide greening materials that exhibit superior erosion resistance even when containing a plasticizer.SOLUTION: Greening materials contain water, polyvinyl acetate, polyvinyl alcohol, and a plasticizer. The volume ratio of the water to the polyvinyl acetate is 80:20 to 99.2:0.8. When the total volume of the water, the polyvinyl acetate, and the plasticizer is 100%, the volume of the polyvinyl alcohol is 0.005 vol.%-0.5 vol.%. When the total weight of the water, the polyvinyl acetate, the polyvinyl alcohol, and the plasticizer is 100 wt.%, the greening materials further contain 0.1 wt.% or more and 2.5 wt.% or less of a thickener and 0.1 wt.% or more and 2.5 wt.% or less of a dispersant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a greening material and a greening method using the same. [Background technology]

[0002] Traditionally, revegetation materials have been used for revegetation work on reclaimed land and other soils. These revegetation materials may contain seeds, fertilizer, etc., and when they are spread on the soil, the seeds germinate, plants flourish, and the soil becomes stabilized.

[0003] Some greening materials have dust-proof properties, erosion resistance, biodegradability, etc. In particular, the greening material disclosed in Patent Document 1 is characterized by its emphasis on biodegradability and by being a resin emulsion or powder thereof that does not contain plasticizers that are suspected of being endocrine disrupting chemicals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3884002 Summary of the Invention [Problem to be solved by the invention]

[0005] Greening materials that contain resin as an active ingredient but do not contain plasticizers have the advantage of not inhibiting seed germination, but they tend to be susceptible to erosion due to rainfall. To compensate for erosion resistance, tasks such as installing a vegetation sheet or re-spraying the greening material are time-consuming. Furthermore, when targeting slopes, the safety of installing the vegetation sheet becomes an issue. Therefore, the present invention aims to provide a greening material that has excellent erosion resistance even if it contains a plasticizer. It also aims to provide a greening method using this greening material. [Means for solving the problem]

[0006] The present invention provides a greening material containing water, polyvinyl acetate, polyvinyl alcohol, and a plasticizer, wherein the volume ratio of water to polyvinyl acetate is 80:20 to 99.2:0.8, the volume of polyvinyl alcohol is 0.005% to 0.5% by volume when the total volume of water, polyvinyl acetate, and plasticizer is 100%, and the greening material further contains 0.1% to 2.5% by weight of a thickener and 0.1% to 2.5% by weight of a dispersant, relative to the total weight of water, polyvinyl acetate, polyvinyl alcohol, and plasticizer.The present invention also provides a greening method in which the greening material is sprayed on sloped soil.

[0007] This greening material has a high plant health rate and excellent erosion resistance, ensuring reliable plant growth even if rain falls after application. Plasticizers added during the manufacturing and distribution processes of the constituent raw materials of the greening material can reduce seed germination rates and subsequent seed health rates. However, because the greening material of the present invention contains components that are effective at low concentrations, the concentration of the plasticizers contained can be reduced accordingly, thereby minimizing the adverse effects on germination rates and seed health rates.

[0008] The greening material of the present invention may contain seeds and fertilizer. When the greening material contains seeds and fertilizer together with components such as polyvinyl acetate, the materials necessary for greening can be applied in one go.

[0009] The revegetation material of the present invention may be one that forms a film on the surface of the soil when applied to the soil, in which case the film provides resistance to rainfall and therefore has excellent erosion resistance. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a greening material that has excellent erosion resistance even when it contains a plasticizer, and also to provide a greening method using this greening material. [Brief explanation of the drawings]

[0011] [Figure 1]10 is a graph showing the dust scattering prevention effect. [Figure 2] Both (A) and (B) are graphs showing the erosion prevention effect. [Figure 3] (A), (B), and (C) are all graphs showing the effects of greening. [Figure 4] (A), (B), and (C) are all graphs showing the effects of greening. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will now be described in detail.

[0013] <Composition of greening materials> The greening material of this embodiment is a liquid mixture to be applied to the surface of the soil, and contains water, polyvinyl acetate, polyvinyl alcohol, a thickener, a dispersant, and a plasticizer. Seeds and fertilizer may also be contained in the material base material made of these materials.

[0014] The volume ratio of water to polyvinyl acetate is 80:20 to 99.2:0.8, and may be 85:15 to 99:1, or 90:10 to 98.5:1.5. When the volume ratio is within this range, the viscosity of the revegetation material is maintained at a suitable level for spraying, and when sprayed on soil, a polymer coating can be formed on the soil surface.

[0015] The polyvinyl alcohol content is 0.005% to 0.5% by volume, assuming the total volume of water, polyvinyl acetate, and plasticizer to be 100%. The lower limit may be 0.01% or 0.05% by volume, and the upper limit may be 0.3% or 0.1% by volume. If the polyvinyl alcohol content is too high, the viscosity of the greening material tends to increase, making it difficult to spray. If the polyvinyl alcohol content is too low, the polyvinyl acetate tends to be less soluble in water. For these reasons, it is preferable that the polyvinyl alcohol content be within the above range.

[0016] Polyvinyl alcohol may exist in the greening material in the form of polyvinyl alcohol molecules, in the form of a residue from emulsion polymerization of vinyl acetate, or in any other form of molecular structure derived from polyvinyl alcohol molecules.

[0017] The composition ratios of water, polyvinyl acetate, and polyvinyl alcohol in greening materials can be measured, for example, by nuclear magnetic resonance spectroscopy (NBR), infrared absorption spectroscopy (IR), size exclusion chromatography (SEC), liquid chromatography (LC), and pyrolysis-mass spectrometry (Pyrolysis-MS).

[0018] Thickeners increase the viscosity of landscaping materials, helping to improve their erosion resistance. This is particularly useful when applying landscaping materials to soils with high moisture content. Furthermore, the inclusion of a thickener in landscaping materials helps prevent the materials from flowing down the slope when applied to the slope. In particular, if the landscaping materials contain seeds, the viscosity of the landscaping materials helps to hold the seeds in place after application, preventing them from flowing down the slope.

[0019] The content of the thickener is 0.1% by weight or more and 2.5% by weight or less, where the total weight of water, polyvinyl acetate, polyvinyl alcohol, and plasticizer is 100% by weight. The lower limit is preferably 0.2%, 0.3%, or 0.4% by weight. The upper limit may be 2.0%, 1.75%, 1.50%, 1.25%, 1.0%, or 0.75% by weight. The viscosity of the greening material also affects the ease of application.

[0020] The content of the thickener may be 0.52% by weight or more and 2.5% by weight or less, where the total weight of water, polyvinyl acetate, polyvinyl alcohol, and plasticizer is 100% by weight. The lower limit is preferably 0.55%, 0.57%, or 0.6% by weight. The upper limit may be 2.0%, 1.75%, 1.50%, 1.25%, 1.0%, or 0.75% by weight. The viscosity of the greening material also affects the ease of application.

[0021] The thickener is preferably water-soluble, and polysaccharides are preferred due to their high biodegradability. Examples of polysaccharides include guar gum, gum arabic, xanthan gum, carboxymethylcellulose, tamarind seed gum, carrageenan, karaya gum, succinoglycan, locust bean gum, soybean polysaccharides, pullulan, psyllium seed gum, curdlan, alginic acid / PGA, gellan gum, glucomannan, agar, and pectin. Among these, guar gum, which is primarily composed of galactomannan, is preferred.

[0022] The dispersant prevents the thickener from agglomerating when mixed and helps dissolve it uniformly in the liquid. The content of the dispersant is 0.1% by weight or more and 2.5% by weight or less, based on 100% by weight of the total weight of water, polyvinyl acetate, polyvinyl alcohol, and plasticizer. The lower limit is preferably 0.2%, 0.3%, or 0.4% by weight. The upper limit may be 2.0%, 1.75%, 1.50%, 1.25%, 1.0%, 0.75%, or 0.65% by weight.

[0023] Dispersants (excluding surfactants) that are liquid or solid at room temperature are used. Here, room temperature refers to 15°C to 25°C. Examples of dispersants that are liquid at room temperature include ethanol, polyethylene glycol, ethylene glycol, 1-propanol, 2-propanol, and 2-butanol. Examples of dispersants that are solid at room temperature include sucrose, capsaicin, dextrin, glucose, fructose, lactose, panotinose, maltooligosaccharide, fructooligosaccharide, polyethylene glycol powder, and polyethylene glycol granules.

[0024] The total content of the thickener and dispersant may be 0.2% by weight or more and 5.0% by weight or less, 0.4% by weight or more and 4.0% by weight or less, 0.6% by weight or more and 3.0% by weight or less, 0.8% by weight or more and 2.0% by weight or less, 0.9% by weight or more and 1.5% by weight or less, or 0.95% by weight or more and 1.3% by weight or less, where the total weight of the water, polyvinyl acetate, polyvinyl alcohol, and plasticizer is 100% by weight.

[0025] The greening material may contain seeds and fertilizer. The seeds may be seeds of bermudagrass, seaside bentgrass, creeping red fescue, perennial ryegrass, or bush clover. The coating formed after the greening material is sprayed is erosion-resistant, making it difficult for rain to penetrate, so a plant species that is resistant to drought is preferred. Bermudagrass is preferred from the standpoint of drought resistance. The amount of seeds mixed may be 0.05% by weight to 1.0% by weight when the material base (composition consisting of water, polyvinyl acetate, polyvinyl alcohol, plasticizer, thickener, and dispersant) is taken as 100% by weight.

[0026] Any type of fertilizer can be used as long as it is one that is normally used as a fertilizer for plants. The amount of fertilizer to be mixed may be 0.3 to 2.5% by weight, assuming that the above-mentioned base material (composition consisting of water, polyvinyl acetate, polyvinyl alcohol, plasticizer, thickener, and dispersant) is 100% by weight and NPK is 15%-15%-15%. Here, N represents nitrogen, P represents phosphorus, and K represents potassium. Based on the area to be sprayed, 10 g / m 2 ~80g / m 2 and 20 g / m 2 ~60g / m 2 may be.

[0027] The greening material of this embodiment contains a plasticizer. The plasticizer is added in trace amounts during the manufacturing or distribution process of the constituent raw materials of the base material. It is not necessary to add a plasticizer, but it is also not necessary to remove the plasticizer contained in the base material. Examples of the plasticizer contained may include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl benzyl phthalate, and other phthalate esters, as well as di-2-ethylhexyl adipate and tributyl acetyl citrate.

[0028] <Preparation and application of greening materials (greening method)> A preferred method for preparing the greening material is to mix and dissolve polyvinyl acetate, polyvinyl alcohol, and a plasticizer in an appropriate amount of water, and then add water to achieve the above-mentioned composition ratio. For example, polyvinyl acetate and polyvinyl alcohol are mixed in water with a volume 1 to 3 times that of polyvinyl acetate (i.e., 25 to 50 volume % polyvinyl acetate), and the mixture is stirred at room temperature or while heated to dissolve. Water is then added so that the overall composition ratio falls within the above-mentioned composition ratio range. A thickener and a dispersant are then added and stirred. If aggregates form at any point, the mixture may be filtered to remove the aggregates. Finally, seeds and fertilizer are mixed. In this manner, the greening material can be prepared.

[0029] The greening material prepared as described above has the above composition ratio, and therefore has appropriate viscosity and is easy to spread. Methods for spreading the greening material include using a hydroseeder (vehicle), an engine pump, a high-washer, etc. The surface to be spread may be flat or a slope.

[0030] <Effects> The greening material of this embodiment contains seeds and fertilizer, allowing the necessary greening materials to be sprayed in one go. The sprayed seeds then germinate, grow, and flourish. Plasticizers added during the manufacturing or distribution process of the constituent raw materials of the greening material can reduce the seed germination rate and health rate (greening materials can prevent seeds from developing roots after germination, resulting in seeds that do not sprout. Health rate = ([number of plants with healthy roots and independent sprouts] / [number of germinated plants]) × 100). However, because each component of the greening material of this embodiment is effective at a low concentration, the concentration of the plasticizer contained is also reduced, thereby minimizing the negative impact on the germination rate and health rate. In the past, if you wanted to eliminate the effects of plasticizers, you had to synthesize each component of the greening material yourself, but the greening material of this embodiment can essentially eliminate the effects of plasticizers in terms of concentration, so it can be effectively prepared by diluting purchased polyvinyl acetate containing plasticizers. Greening materials prepared in this way can still achieve their greening goals without inhibiting seed germination or subsequent growth.

[0031] When the revegetation material of this embodiment is applied to soil, it forms a coating on the soil surface within approximately 24 hours. This coating provides resistance to rainfall, making the soil highly resistant to erosion. Even if the revegetation material is diluted by the water in the soil, the thickener contained in the revegetation material allows for the formation of a sufficient coating. For example, when the soil has a high moisture content, such as immediately after rainfall, the revegetation material may be diluted by the water in the soil. However, the viscosity of the thickener increases, making it less likely to penetrate the soil. Therefore, a coating is formed on the soil surface, providing an erosion prevention effect. This coating also prevents dust from scattering from the surface of the soil.

[0032] As a result of the above, in the short term, the effects of preventing erosion and dust dispersion appear immediately after spraying. In the long term, as the seeds germinate and grow, greening progresses and the rooted plants take on these effects. In this way, slope protection and greening are achieved by spraying the revegetation material of this embodiment.

[0033] Furthermore, when a highly biodegradable polysaccharide is used as a thickener, biodegradation of polyvinyl acetate can also be expected. Although polyvinyl acetate is inherently poorly biodegradable, the present inventors have found that it becomes more biodegradable when coexisting with a highly biodegradable polysaccharide.

[0034] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. [Example]

[0035] The present invention will be described in more detail below with reference to specific experimental examples, but the present invention is not limited to the following experimental examples.

[0036] <Preparation of greening materials> Greening materials consisting of water, polyvinyl acetate, polyvinyl alcohol (PVA), thickener, dispersant, seeds, and fertilizer were prepared according to the formulations shown in Table 1. Commercially available polyvinyl acetate containing and not containing plasticizers were used. Guar gum was used as the thickener. Polyethylene glycol powder was used as the dispersant. Seeds were a mixture of bermudagrass, seaside bentgrass, creeping red fescue, perennial ryegrass, and medlar, and were applied at 8-14g / m². 2 The fertilizer used was the advanced compound fertilizer "15-15-15" at 50g / m 2 Used.

[0037] The greening material was prepared by placing the base material (polyvinyl acetate, PVA, thickener, dispersant) in a tank, and then adding water and the thickener and dispersant while stirring. Water was added until the total volume reached 800 mL. Seeds and fertilizer were then added. The greening material prepared in this way was used for the following tests. The spray rate for flat surfaces was 2 L / m. 2 , 3L / m for slopes 2 It was decided.

[0038] <Dust scattering prevention test> The greening materials were spread on a slope with a gradient of 10% using a hydroseeder. After spreading, the slope erosion and greening conditions were observed for seven months. The greening materials were mixed as follows: Section 1: Standard seed spraying method (8 g / m 2 ), Section 2: The amount of seeds was increased by 1.7 times compared to the standard mixture (14 g / m) to provide sufficient margin. 2 ), Section 3: The amount of seeds was increased by 1.3 times (11 g / m) to take into account the germination inhibition in the laboratory test. 2 ), Section 4: Straw greening sheet with seeds (conventional method) were set respectively.

[0039] Vegetation coverage was measured three and seven months after construction. Using the quadrat method, vegetation coverage was measured at 60% in Sections 2 and 3 and 70% in Section 1 after seven months. In Section 1, the slope revegetation work was rated "fair" (vegetation coverage ≥ 70%). In Section 4, vegetation coverage was 80%, but rainfall erosion was observed on the upper slope where the revegetation sheet was not installed. In contrast, no erosion was observed in Sections 1-3. Although the vegetation coverage was slightly lower than that of the revegetation sheet, it was determined that the application of revegetation materials had achieved erosion prevention and greening. Cumulative dust dispersion was measured after 2, 14, 30, 60, 90, 120, 150, and 180 days. The results, based on the following evaluation criteria, are shown in Table 1. Evaluation criteria A: The amount of dust released after 180 days is less than 0.02g. B...The amount of dust dispersed after 180 days is 0.02g or more.

[0040] Figure 1 shows data for an example where no revegetation materials were sprayed, Experimental Example 5, which received an A rating, and Experimental Example 6, which received a B rating. The results show that Experimental Example 5, which contained a thickener, was able to keep the amount of dust flying lower than Experimental Example 6, which did not contain a thickener.

[0041] <Erosion resistance test> Erosion resistance tests were conducted using an artificial rainfall device. A construction fiber sheet was laid in a metal tray (23cm x 19cm x 3cm) with many holes in the bottom, and soil was then spread on top of it. Each formulation of revegetation material, which did not contain seeds or fertilizer, was then spread on the soil. The soil was then allowed to cure for three days to form a film.

[0042] The tub was placed under an artificial rainfall device so that the soil surface was at a 45-degree angle to the horizontal. The artificial rainfall device was operated to cause rain to fall on the soil in the tub. The rainfall rate was 80 mm / hour. The soil surface runoff was collected in pitchers, which were replaced with new pitchers every 10 minutes. The turbidity of the water collected in each pitcher was measured using a TD-M500 (Optex Co., Ltd.). The results are shown in Table 1. Evaluation criteria A: The turbidity after 60 minutes is 10 FTU or less. B: Turbidity after 60 minutes is greater than 10 FTU and less than 100 FTU. C: Turbidity exceeds 100 FTU after 60 minutes.

[0043] A time-lapse graph is shown in Figure 2, along with an example where no revegetation materials were sprayed. In the test specimens containing a certain amount of thickener, the turbidity was low, indicating that there was almost no soil erosion or runoff.

[0044] <Greening test> Cylindrical pots (Neubauer pots 1 / 10000a) with a diameter of 11.3 cm were filled with soil and then the revegetation material containing seeds and fertilizer was sprayed on. After spraying, the seeds were left to cure at room temperature for two days to allow a coating to form. They were then cultured in a thermostatic chamber. The culture conditions were a temperature of 20°C, humidity of 70%, and moisture content of 60%. After two weeks, the germination rate, health rate, and maximum elongation were determined. The results are shown in Table 1. Evaluation indicators "Germination rate": ([Number of germinated individuals] / [Number of scattered seeds]) x 100 "Health rate": ([Number of plants with healthy root growth and independent sprouts] / [Number of germinated plants]) x 100 "Maximum elongation": The length of the tallest aboveground part of a germinated individual ·Evaluation criteria for soundness rate A…90% or more and 100% or less. B: 80% or more but less than 90%. C...less than 80%.

[0045] Graphs of the germination rate, health rate, and maximum elongation are shown in Figures 3 and 4, along with an example where no revegetation materials were sprayed. In Experimental Example 1, revegetation was possible, but the health rate and maximum elongation were poor. In Experimental Example 4, the germination rate was poor, but the health rate and maximum elongation were excellent.

[0046] <Biodegradability test> An aerobic ultimate biodegradability test in soil (based on JIS K6955:2006) was conducted. The film of each material was crushed and the carbon content of the specimen (ThCO2) was measured. 400g of field soil and 1g of specimen were placed in a 500mL test container and incubated at approximately 25°C, with the amount of CO2 generated being measured periodically. At the same time, the amount of CO2 generated in the blank test (BLCO2) was also measured, and the biodegradability was calculated using the following formula. All tests were conducted with n=2. Biodegradability (%) = {(CO2 generated by test specimen (mg) - BLCO2 generated (mg)) / ThCO2 (mg)} x 100 Evaluation criteria A...Showed biodegradability. D: Not biodegradable.

[0047] Experimental Examples 1 to 5 showed biodegradability, but Experimental Example 6 did not show biodegradability.

[0048] [Table 1] [Industrial Applicability]

[0049] The present invention can be used, for example, for greening constructed slopes.

Claims

1. A greening material containing water, polyvinyl acetate, polyvinyl alcohol, and a trace amount of plasticizer, a volume ratio of the water to the polyvinyl acetate of 80:20 to 99.2:0.8; the volume of the polyvinyl alcohol is 0.005% by volume to 0.5% by volume when the total volume of the water, the polyvinyl acetate, and the plasticizer is 100%; The greening material further contains 0.1% by weight to 2.5% by weight of a thickener and 0.1% by weight to 2.5% by weight of a dispersant, with the total weight of the water, the polyvinyl acetate, the polyvinyl alcohol, and the plasticizer being 100% by weight.

2. The greening material according to claim 1, comprising seeds and fertilizer.

3. 3. The greening material according to claim 1, which forms a coating on the surface of the soil when applied to the soil.

4. A greening method comprising spraying the greening material according to claim 3 onto soil on a slope.

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