TW202317738A - Emulsion composition and soil erosion inhibitor - Google Patents

Abstract

Provided is an emulsion composition and a soil erosion inhibitor in which aggregation does not occur even after repeated freezing and thawing. The present invention provides an emulsion composition configured such that, when a change in temperature of each row in table 1, the change being initiated from high to low, is taken as a temperature cycle, after 10 repetition of this temperature cycle, the fineness modulus obtained when the emulsion composition filtered using a 200 mesh wire screen is 500 ppm or less. The temperature change in each row results from changing the temperature from the start temperature to the end temperature or maintaining a temperature during the retention time.

Description

Emulsion composition and anti-soil erosion agent

The present invention relates to emulsion composition and anti-soil erosion agent.

Filling or cutting soil in the construction of level ground, roads, dams, etc. If the resulting slope is placed directly, it will be eroded by rainfall or weathering, resulting in accidents such as landslides and rockfalls. Therefore, in Patent Document 1, soil erosion is prevented by spraying the following spraying material on the slope, and the above spraying material is formulated with an emulsion composition at a ratio of 0.5 to 1.5 kg per 1 m ³ of the spraying material. [Prior Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent No. 4048800

[Problem to be solved by the invention]

Materials used for slope construction may be stored in warehouses or the like, and may be stored covered with cloth or the like after transported to the construction site. In winter in cold regions, the temperature of some storage places may even be lower than 0°C. In this case, there will be problems such as freezing and coagulation of the emulsion composition used as an anti-soil erosion agent. Especially when freezing and thawing are repeated, there is a problem that the emulsion composition coagulates.

The present invention has been made in view of such a problem, and provides an emulsion composition and a soil erosion control agent that do not aggregate even after repeated freezing and thawing. [means to solve the problem]

According to the present invention, an emulsion composition is provided, wherein, the temperature cycle in which the temperature of each line is changed in the order from top to bottom in the following table is regarded as a cycle, and after repeating the temperature cycle 10 times, when filtering with a 200-mesh metal mesh The coarse particle rate is 500ppm or less, and the temperature change of each row is performed by changing or maintaining the starting temperature to the ending temperature during the holding time.

Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other. The emulsion composition preferably contains a water-soluble resin emulsion, a water-soluble polymer, and a surfactant. Preferably, the mass ratio of the water-soluble polymer to the surfactant in the emulsion composition is 7:1-1:7.

According to another aspect of the present invention, an emulsion composition is provided, which contains a water-soluble resin emulsion, a water-soluble polymer, and a surfactant, and the mass ratio of the content of the water-soluble polymer to the content of the surfactant is 7 :1~1:7.

The emulsion composition preferably contains 1 to 6% by mass of the water-soluble polymer and the surfactant in total. Preferably, the water-soluble resin emulsion is an emulsion of a resin containing a structural unit derived from vinyl acetate. Preferably, the water-soluble resin emulsion is an ethylene-vinyl acetate copolymer emulsion.

According to another aspect of the present invention, there is provided a soil erosion control agent comprising the above emulsion composition.

Embodiments of the present invention will be described below. Various characteristic matters shown in the embodiments shown below can be combined with each other. In addition, each feature may independently constitute an invention.

1. Emulsion composition The emulsion composition according to one aspect of the present invention is an emulsion composition in which the temperature cycle in which the temperature of each row is changed in order from top to bottom in Table 1 below is regarded as one cycle, and the temperature cycle is repeated 10 times. , when filtered with a 200-mesh metal mesh, the coarse particle rate is below 500ppm. The temperature change of each row is performed by changing or maintaining from the start temperature to the end temperature during the hold time.

[Table 1]

The temperature cycles of Table 1 can be represented as a graph in Figure 1. Such a temperature change can be performed using a test device capable of changing temperature, such as an environmental tester.

In addition, the coarse particle rate is the ratio (ppm) of the mass of the filtration residue to the mass of the emulsion composition obtained when the emulsion composition is filtered using a metal mesh with a mesh size of 200 mesh.

An emulsion composition according to one aspect of the present invention contains a water-soluble resin emulsion, a water-soluble polymer, and a surfactant. The mass ratio of the water-soluble polymer content to the surfactant content in the emulsion composition is preferably 7:1 to 1:7, more preferably 5:1 to 1:7, and even more preferably 1:1 to 1:7 . By setting it within this range, the strength when formed into a film is excellent, the effect as a soil erosion preventive agent is high, and the handleability due to the moderate viscosity is excellent, and the freeze-thaw stability is also excellent. In addition, when the content of the surfactant is too large, the strength of the film may be low, and the effect of preventing soil erosion may not be obtained. When there is too little content of surfactant, freeze-thaw stability may fall. In addition, when the content of the water-soluble polymer is too large, the viscosity may increase and the handling properties may decrease. Moreover, when there is too little content of a water-soluble polymer, freeze-thaw stability may fall.

The emulsion composition contains a total of preferably 1 to 6% by mass, more preferably 2 to 4% by mass of a water-soluble polymer and a surfactant. By setting it in this range, the viscosity suitable for handleability can be obtained, and the effect of preventing soil erosion can be acquired. In addition, it is also excellent in freeze-thaw stability. If the total content of these is too high, not only the cost is high, but also the viscosity may be too high, and the effect of preventing soil erosion may also be reduced. Moreover, when these total content is too small, freeze-thaw stability may fall. The total content of the water-soluble polymer and the surfactant is specifically, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0% by mass, and may be between any two numerical values exemplified here. In the range.

＜Water-soluble resin emulsion＞ The water-soluble resin emulsion uses water as the dispersion medium and resin as the dispersant. As the water-soluble resin emulsion, for example, a water-soluble resin emulsion prepared by using various olefinic compounds such as vinyl acetate, acrylate, styrene, ethylene, and butadiene as main monomers alone or by polymerization of multiple types can be used. Specifically, vinyl acetate resin emulsion, vinyl acetate copolymer emulsion, acrylate resin emulsion, styrene acrylate copolymer emulsion, ethylene-vinyl acetate copolymer emulsion, styrene-butadiene copolymer emulsion , vinylidene resin emulsion, polybutene resin emulsion, acrylonitrile butadiene resin emulsion, methacrylate-butadiene resin emulsion, asphalt emulsion, epoxy resin emulsion, urethane resin emulsion, silicone resin emulsion Among them, emulsions of resins containing structural units derived from vinyl acetate (vinyl acetate resin emulsions, vinyl acetate copolymer emulsions, ethylene-vinyl acetate copolymer emulsions, etc.) are preferred, and ethylene-vinyl acetate copolymer emulsions are more preferred. animal emulsion.

The method for producing the water-soluble resin emulsion is not particularly limited. For example, an emulsifier and a monomer are added to a dispersion medium mainly composed of water, and the monomer is emulsified and polymerized while stirring. Examples of emulsifiers include polymer additives such as hydroxyethylcellulose, methylcellulose, and polyvinyl alcohol. The polymer additive is particularly preferably an additive composed of polyvinyl alcohol, and its average degree of polymerization is, for example, 200-2500, preferably 400-2200, more preferably 500-2000. The greater the average degree of polymerization of polyvinyl alcohol, the higher the emulsification dispersibility. Therefore, in order to obtain an emulsion with a desired degree of dispersion, polyvinyl alcohol having an appropriate average degree of polymerization may be used. In addition, multiple types of polyvinyl alcohols having different average degrees of polymerization may be used in combination. The degree of saponification of polyvinyl alcohol is not particularly limited, but is, for example, 70% or more, preferably 80 to 95%. If the saponification is too low, the solubility in water is extremely low, and a special dissolution method is required to dissolve it, making it difficult to be used industrially. The lower the saponification degree of polyvinyl alcohol is, the higher the emulsification dispersibility is. Therefore, in order to obtain an emulsion with a desired dispersion degree, polyvinyl alcohol having an appropriate degree of saponification may be used. Various emulsifiers can be used in combination.

It should be noted that polymer additives such as polyethylene glycol and polyvinyl alcohol used as emulsifiers in the production of water-soluble resin emulsions can be regarded as water-soluble polymers contained in the emulsion composition.

＜Water-soluble polymer＞ The water-soluble polymer is preferably a water-soluble polymer with a surface tension of 40mN/m-75mN/m measured by the Wilhelmy method under the conditions of an aqueous solution concentration of 0.1wt% and an aqueous solution temperature of 25°C. Examples include methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, aminomethyl hydroxy Propyl cellulose, aminoethyl hydroxypropyl cellulose and other cellulose derivatives; starch, carrageenan, mannan, agarose, dextran, tragacanth gum, pectin, glue, alginic acid or its salt Gelatin; Polyvinylpyrrolidone; Polyacrylic acid or its salt; Polymethacrylic acid or its salt; Polyacrylamide, polymethacrylamide and other acrylamides; Hyaluronic acid and its salt, Chondroitin sulfate and its Salt, polyvinyl alcohol, polyethyleneimine, polyethylene oxide, polyethylene glycol, polypropylene glycol, etc. These substances may be used alone or in any combination. In one embodiment, the emulsion composition preferably contains a cellulose derivative and a high molecular weight alcohol.

The content of the water-soluble polymer in the emulsion composition is preferably 0.01 to 3.0% by mass, more preferably 0.1 to 2.5% by mass. By setting it in this range, the handleability by suitable viscosity is excellent, and it is also excellent in freeze-thaw stability. In addition, the content of polymer alcohols such as polyethylene glycol and polyvinyl alcohol in the emulsion composition is preferably 0.01 to 1.0% by mass, more preferably 0.1 to 0.5% by mass.

The method of adding the water-soluble polymer is not particularly limited, and may be added as an emulsifier during the production of the water-soluble resin emulsion, or may be added separately after the production of the water-soluble resin emulsion.

＜Surfactant＞ The surfactant is preferably a surfactant having a surface tension of 25mN/m to 45mN/m as measured by the Wilhelmy method under the conditions of an aqueous solution concentration of 0.1wt% and an aqueous solution temperature of 25°C. Anionic・amphoteric) surfactant or nonionic (nonion) surfactant. As a cationic surfactant, a quaternary ammonium salt, an amine salt, etc. are mentioned, for example. Examples of anionic surfactants include lauryl sulfate, alkylbenzenesulfonate, alkylphenyl ether sulfate, methyl taurate, sulfosuccinate, ethersulfonate, Phosphate ester salt, alkyl ether sulfate ester salt, etc. Examples of the amphoteric surfactant include alkylcarboxybetaine and the like. Examples of nonionic surfactants include polyoxyethylene alkylaryl ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene styrenated phenylene ether, polyoxyethylene oleyl ether, and polyoxyethylene lauryl ether. Polyoxyethylene ethers or polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, etc. Ethylene fatty acid esters, polyoxyethylene/polyoxypropylene block copolymers, etc. Among them, the surfactant preferably has a benzene ring-containing structure. In addition, as the nonionic surfactant, polyoxyethylene styrenated phenylene ether polyoxyalkylene alkyl ether is preferable. These substances may be used alone or in any combination.

The content of the surfactant in the emulsion composition is preferably 0.1 to 5.0% by mass, more preferably 0.5 to 3.5% by mass. By setting it within this range, the strength when formed into a film is excellent, the effect as a soil erosion preventive agent is high, and it is also excellent in freeze-thaw stability.

The method of adding the surfactant is not particularly limited, and may be added during the production of the water-soluble resin emulsion, or may be added separately after the production of the water-soluble resin emulsion. It is preferable to add it separately after manufacture of a water-soluble resin emulsion.

2. Anti-soil erosion agent The soil erosion prevention agent which concerns on one Embodiment of this invention is a soil erosion prevention agent containing an emulsion composition. Plasticizers, tackifying resins, tackifiers, defoamers, pH regulators, humic acids, amino acids, herbicides, pesticides, etc. can be added as needed.

The method of spraying the soil erosion preventive agent on the soil is not particularly limited. For example, a watering can or a power spreader can be used for small area spraying, and a hydraulic seeder or boom sprayer can be used for large area spraying. In addition, the sprayed anti-soil erosion agent plays the role of forming a consolidated layer composed of the silt body of the powder-grained accumulation and the anti-soil erosion agent on the granular accumulation, and keeps the rainwater flowing into the consolidated layer, Reducing the amount of water flowing into the powder and granular deposits under the consolidated layer can show the effect of preventing the powder and granular deposits from collapsing and flowing out. In addition, by forming a consolidated layer, an effect of preventing dust generation can also be exhibited.

In addition, the anti-soil erosion agent can be sprayed on the protective surface alone, or it can be sprayed on the protective surface together with the spraying material that is mainly composed of soil and mixed with seeds, bark compost or fertilizer. The method of spraying the spraying material on the object surface is not particularly limited, for example, the seed spreading method, the soil spraying method, the base material spraying method, etc., or in the case of a large object surface, can also be sprayed from a helicopter, etc. Aircraft spray to spray. [Example]

The following examples are given to further describe the present invention in detail. In addition, these Examples are only illustrations, and the content of this invention is not limited to these.

＜Preparation of water-soluble resin emulsion 1 (EVA1)＞ EVA1 was prepared according to the conditions in Table 2. Drop into the high-pressure polymerization tank with stirrer in advance in the pure water of 100 mass parts and be dissolved with the solution of following composition: Polyvinyl alcohol (DENKA POVAL B-05 (saponification degree 88mol%, average polymerization degree 600, DENKA Co., Ltd.) 3.4 parts by mass, DENKA POVAL B-17 (saponification degree 88 mol%, average polymerization degree 1700, DENKA Co., Ltd.) 0.7 parts by mass, Pluronic L-64 (Adeka Co., Ltd.) 0.2 parts by mass, as an auxiliary agent 0.2 parts by mass of formamidine sulfinic acid, 0.2 parts by mass of sodium acetate, 0.005 parts by mass of ferrous sulfate heptahydrate, and 0.01 parts by mass of tetrasodium ethylenediamine tetraacetate, and then filled with 33 parts by mass of vinyl acetate monomer under stirring and 22 parts by mass of vinyl monomer, and adjust the temperature of the inner liquid to 55° C. Add 10 mass % ammonium persulfate aqueous solution to start polymerization. Continuously add 57 parts by mass of vinyl acetate monomer and ethylene mono Body 17 mass parts, and 2.7 mass parts of 10 mass % ammonium persulfate aqueous solution (total with the initial addition amount) and 0.9 mass parts of 10 mass % tert-butyl hydroperoxide aqueous solution as additives added in batches are polymerized. Continue to polymerize until The amount of unreacted vinyl acetate monomer was less than 2%. The remaining ethylene after the polymerization was purged, and the unreacted vinyl acetate monomer in the resulting emulsion was removed under reduced pressure to obtain EVA1. The water-soluble polymer (polyvinyl alcohol: PVA) in EVA1 was 1.7 mass %, and the surfactant was 0.08 mass %.

＜Preparation of water-soluble resin emulsion 2 (EVA2)＞ EVA2 was prepared according to the conditions in Table 2. Drop into the high-pressure polymerization tank with stirrer in advance in the pure water of 100 mass parts and be dissolved with the solution of following composition: Polyvinyl alcohol (DENKA POVAL B-05 (saponification degree 88mol%, average polymerization degree 600, DENKA Co., Ltd.) 4.1 parts by mass, DENKA POVAL B-17 (saponification degree 88 mol%, average polymerization degree 1700, Denka Co., Ltd.) 1.5 parts by mass, formamidine sulfinic acid as an auxiliary agent 0.1 mass part, sodium acetate 0.2 mass part, 0.005 mass part of ferrous sulfate heptahydrate, 0.01 mass part of tetrasodium ethylenediaminetetraacetate, thereafter, under stirring, fill 83 mass parts of vinyl acetate monomer and 20 mass parts of ethylene monomer, the inner liquid temperature is adjusted to 55° C. Add 10 mass % ammonium persulfate aqueous solution to start polymerization. Continuously add 26 mass parts of vinyl acetate monomer as batch addition monomer and 2.0 mass parts of 5 mass % ammonium persulfate aqueous solution as batch addition additive (total with the initial addition amount) and 0.6 mass parts of 10 mass % tert-butyl hydroperoxide aqueous solution are polymerized.Continuous polymerization is less than 2% to the amount of unreacted vinyl acetate monomer. The residual ethylene after the polymerization is purged, and the unreacted vinyl acetate monomer in the resulting emulsion is removed under reduced pressure to obtain EVA2. The water-soluble polymer (polyvinyl alcohol: PVA) in EVA2 was 2.4 mass %, and the surfactant was 0 mass %.

[Table 2]

[Examples 1 to 11, Comparative Example 1] Mix the water-soluble resin emulsion (EVA1 or EVA2), water, surfactant, and required water-soluble polymer according to the respective formulation ratios in Table 3 to prepare the emulsion composition. Table 3 also shows the total contents of the water-soluble polymers and surfactants contained in the emulsion composition.

In addition, each compound in Table 3 is as follows. HEC200: Hydroxyethylcellulose (Viscosity of 2% aqueous solution (20°C): 200~300mPa･s, manufactured by Tokyo Chemical Industry Co., Ltd.) Cellogen WS-C: Carboxymethylcellulose (Viscosity of 1% aqueous solution (25°C): 150~250mPa･s, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) NOIGEN EA-137: Polyoxyethylene styrenated phenylene ether (HLB value: 13.0, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) NOIGEN EA-87: polyoxyethylene styrenated phenylene ether (HLB value: 10.6, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) Emulgen 1150S-60: polyoxyethylene alkyl ether (HLB value: 18.5, manufactured by Kao Corporation) NOIGEN LF-60X: polyoxyalkylene alkyl ether (HLB value: 13.3, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.)

In addition, Table 4 shows the surface tensions of the water-soluble polymers and surfactants used. In addition, the surface tension was measured under the following conditions (measuring device: automatic surface tension meter DY-300 manufactured by Kyowa Interface Science Co., Ltd.). Measuring temperature: 25°C Aqueous solution concentration: 0.1wt% Measuring method: Wilhelmy method (platinum plate)

＜Viscosity＞ The viscosity was measured for the emulsion composition before undergoing the temperature change of the temperature cycle shown in Table 1. The viscosity was measured under conditions of a temperature of 30° C. and a rotation speed of 30 rpm (measuring device: TV-33 type viscometer manufactured by Toki Sangyo Co., Ltd.).

<Coarse particle rate> The coarse particle rate was measured for the emulsion composition before the temperature change of the temperature cycle in Table 1. The temperature cycle in which the temperature of each row in Table 1 was changed in order from top to bottom was regarded as one cycle. The coarse particle rate of the emulsion composition after 10 times of this temperature cycle was measured. The coarse particle rate is calculated by taking the emulsion composition before and after the temperature change of the temperature cycle as a sample, and measuring the mass _M of the filter residue according to JIS K 6828 using a metal mesh with a mesh of 200 meshes. , and the ratio (=[M ₁ /M ₀ ]) to the mass of the sample (emulsion composition M ₀ ) was calculated in ppm. In addition, the temperature change of the temperature cycle of Table 1 was controlled by the environmental testing machine (PR-3K by ESPEC Corporation).

[table 3]

【Table 4】

FIG. 1 is a graph showing a temperature cycle for verifying stability against freeze-thaw of an emulsion composition.

Claims (8)

An emulsion composition, wherein, the temperature cycle in which the temperature of each line is changed in the order from top to bottom in the following table is regarded as a cycle, and after repeating the temperature cycle 10 times, the coarse particle rate when filtering with a 200-mesh metal mesh is Below 500ppm, the temperature change of each row is performed by changing or maintaining from the start temperature to the end temperature during the holding time.

The emulsion composition as claimed in item 1, which contains a water-soluble resin emulsion, a water-soluble polymer and a surfactant. The emulsion composition as described in claim item 2, wherein, The mass ratio of the water-soluble polymer to the surfactant is 7:1-1:7. An emulsion composition, which contains a water-soluble resin emulsion, a water-soluble polymer and a surfactant, The mass ratio of the content of the water-soluble polymer to the content of the surfactant is 7:1-1:7. The emulsion composition according to any one of claims 2 to 4, which contains a total of 1 to 6% by mass of the water-soluble polymer and the surfactant. The emulsion composition as described in any one of claim items 2 to 4, wherein, The water-soluble resin emulsion is an emulsion of a resin containing structural units derived from vinyl acetate. The emulsion composition as described in any one of claim items 2 to 4, wherein, The water-soluble resin emulsion is an ethylene-vinyl acetate copolymer emulsion. An anti-soil erosion agent, which contains the emulsion composition described in any one of claims 1 to 7.

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