A long-acting dripping agent and its production method

Abstract

The present application relates to the field of coating technology, and in particular to a long-lasting dripping agent and a production method thereof. A long-lasting dripping agent, in parts by mass, comprises 10-30 parts of nano-aluminum sol, 8-20 parts of surfactant, 3-8 parts of polyvinyl alcohol resin, 20-60 parts of acrylic polymer, and 25-75 parts of water; the raw material of the acrylic polymer comprises an unsaturated carboxylic acid monomer, which accounts for 4.3-18.5% of the total mass of the polymerized monomers of the acrylic polymer; the carboxyl-containing acrylic polymer and the hydroxyl groups of the vinyl alcohol resin, the hydrophilic groups in the surfactant, and the hydroxyl groups of the nano-aluminum sol all have a strong interaction force, so that the prepared dripping agent not only has good hydrophilicity and adhesion performance, but also the formed film layer has a strong cohesive force, thereby making the dripping agent have a long-term dripping effect.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and in particular to a long-lasting dripping agent and a production method thereof. Background Art

[0002] my country is a major agricultural country, and agricultural production relies on the use of greenhouse film. Greenhouse film can reduce field humidity, mitigate the incidence of pests and diseases, and improve crop yield and quality. However, greenhouse film has poor fog and drip performance. Especially in winter, water produced by crop respiration accumulates on the film, forming droplets. This causes incident light to reflect or refract, reducing the film's transmittance and affecting crop photosynthesis. Furthermore, the droplets fall onto crop leaves, forming a film that creates conditions for pathogens to invade and thrive, leading to vegetable diseases.

[0003] To improve the mist and drip resistance of greenhouse film, the water mist collected on the film is allowed to drip down the greenhouse wall, enhancing the drip resistance and forming a drip-resistant film. Drip-resistant films can be divided into internally added and externally coated types. Internally added greenhouse films have poor drip resistance, while coated types are more widely used. Externally coated greenhouse films are produced by spraying a drip-resistant agent on the film and then drying it. Existing drip-resistant agents are primarily formulated with aluminum sol and silica sol, with a surfactant added for surface modification to improve the film's drip resistance.

[0004] However, the existing film has a good effect in eliminating fog and dripping in the initial stage of use. After a period of use, the film will have serious water droplets, and sometimes the film will turn white and the coating will fall off, seriously affecting farmers' subsequent production and use. The main reason for the above problems is that the film layer formed on the film has poor adhesion and low cohesion, resulting in poor long-term dripping of the film. Summary of the Invention

[0005] In order to solve the problem that the film layer formed by the existing dripping agent has poor adhesion and low cohesion, resulting in poor long-term dripping, the present application provides a long-lasting dripping agent and a production method thereof.

[0006] In the first aspect, the present application provides a long-acting drip:

[0007] A long-acting dripping agent comprises, by weight, 10-30 parts of nano-aluminum sol, 8-20 parts of surfactant, 3-8 parts of polyvinyl alcohol resin, 20-60 parts of acrylic acid polymer and 25-75 parts of water; the raw material of the acrylic acid polymer comprises an unsaturated carboxylic acid monomer, and the unsaturated carboxylic acid monomer accounts for 4.3-18.5% of the total weight of the polymerized monomers of the acrylic acid polymer.

[0008] By adopting the above technical solution, the carboxyl-containing acrylic polymer and the hydroxyl groups of the vinyl alcohol resin, the hydrophilic groups in the surfactant and the hydroxyl groups of the nano-aluminum sol all have strong interaction forces, so that the prepared dripping agent not only has good hydrophilicity and adhesion properties, but also the formed film layer has strong cohesive force, thereby making the dripping agent have a long-term dripping effect.

[0009] Preferably, the weight ratio of the hard monomer to the soft monomer in the acrylic polymer is (0.32-1):1.

[0010] By adopting the above technical solution and optimizing the weight ratio of hard monomer to soft monomer, the flexibility and adhesion performance of the film layer formed by the long-lasting dripping agent can be improved, thereby improving the long-term dripping effect of the dripping agent.

[0011] Preferably, the raw materials of the acrylic polymer include, by weight, 80-120 parts of water, 1-5 parts of emulsifier, 50-76 parts of soft monomer, 24-50 parts of hard monomer, 5-25 parts of unsaturated carboxylic acid monomer, and 0.3-1.5 parts of polymerization initiator; the initiator is persulfate, and the reaction temperature is 80-95°C;

[0012] The unsaturated carboxylic acid monomer is at least one of acrylic acid, fumaric acid, methacrylic acid, itaconic acid, and maleic acid.

[0013] By adopting the above technical solution, a carboxyl-containing acrylic polymer with good adhesion, flexibility and hydrophilicity is prepared, thereby improving the long-term dripping effect of the dripping agent.

[0014] Preferably, the raw material of the acrylic polymer further includes 8-15 parts by mass of a cross-linking monomer, and the cross-linking monomer is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethyl acrylamide, and diacetone acrylamide.

[0015] By adopting the above technical solution, a cross-linking monomer is used in the raw material of the acrylic polymer, and the cross-linking monomer contains a hydroxyl group or an amine group / amino group, so that the carboxyl group in the acrylic polymer and the hydroxyl group, amine group, and amino group can form a strong interaction force, further enhancing the interaction between the acrylic polymers, and between the acrylic polymer and the vinyl alcohol resin, surfactant, and nano-aluminum sol, further enhancing the hydrophilicity and adhesion performance of the acrylic polymer, and thereby enhancing the long-term dripping effect of the dripping agent.

[0016] Preferably, the cross-linking monomer is hydroxyethyl acrylate and N-hydroxymethyl acrylamide in a mass ratio of 1:(2-3).

[0017] By adopting the above technical solution, the type and amount of cross-linking monomers are prioritized to further improve the adhesion and hydrophilicity of the acrylic polymer. At the same time, a strong interaction force is established between the acrylic polymer and the vinyl alcohol resin, surfactant and nano-aluminum sol, further improving the long-term dripping effect of the long-acting dripping agent.

[0018] Preferably, the raw material of the acrylic polymer further comprises 1-5 parts by mass of divinyl-1,4-butanediol ether.

[0019] By adopting the above technical solution and using divinyl-1,4-butanediol ether, the flexibility and adhesion performance of the film layer formed by the long-acting dripping agent are further improved, and the long-term dripping effect of the long-acting dripping agent is further improved.

[0020] Preferably, the long-acting dripping agent further comprises 0.001-0.01 parts by mass of a persulfate initiator and 1-3 parts by mass of hydroxyl-terminated polybutadiene.

[0021] By adopting the above technical solution, using terminal hydroxyl polybutadiene and persulfate initiator, the terminal hydroxyl polybutadiene can undergo polymerization reaction with the unsaturated bonds in the acrylic polymer, so that the long-lasting drip agent forms a film layer with a cross-linked structure, which can improve the cross-linking density, cohesion and adhesion performance, and further improve the long-term dripping effect of the long-lasting drip agent.

[0022] Preferably, the surfactant is at least one of silicone polyoxyethylene ether, sorbitan lauryl ester, emulsifier OP-10, fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, hydroxypropyl methylcellulose, sodium alginate, oleic acid, isomerized fatty alcohol polyoxyethylene ether, dodecyl dihydroxyethyl betaine, sodium dodecylaminopropionate, and dodecyl betaine.

[0023] Preferably, the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:(0.8-1.5):1.

[0024] By adopting the above technical solution, sodium ricinoleate sulfate and sorbitan laurate have more hydrophilic groups and long alkyl chains, which can better promote the emulsification and dispersion effect of the long-lasting drip agent, thereby improving the transmittance and reducing the haze; sodium alginate has more hydrophilic groups, which improves the drip effect and prolongs the initial drip time; the molecular structure of sodium ricinoleate sulfate contains carbon-carbon double bonds. During the film formation process, under the action of an initiator, it can undergo polymerization reaction with the unsaturated bonds in raw materials such as hydroxypolybutadiene and acrylic polymer, thereby improving the crosslinking density, cohesion and adhesion performance of the film layer formed by the long-lasting drip agent, and reducing the migration and loss of the emulsifier during use; when the long-lasting drip agent uses persulfate initiator and terminal hydroxy polybutadiene, the surfactant is used in combination with sorbitan laurate, sodium ricinoleate sulfate and sodium alginate, and their dosage is optimized, which further improves the long-lasting period, initial drip time and transmittance of the long-lasting drip agent and reduces the haze.

[0025] In a second aspect, the present application provides a method for producing a long-acting dripping agent:

[0026] A method for producing a long-acting dripping agent, the preparation process of which is as follows:

[0027] The surfactant and the nano-aluminum sol are stirred and mixed to prepare a first mixture;

[0028] The polyvinyl alcohol resin, the acrylic acid polymer and water are stirred and mixed to prepare a second mixed solution;

[0029] The first mixture is added to the second mixed liquid and stirred to prepare a long-acting dripping agent.

[0030] By adopting the above technical solution, a dripping agent with good hydrophilicity, adhesion performance and strong cohesion is prepared, so that the film layer formed by the dripping agent has a long-term dripping effect.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. A long-lasting dripping agent comprising, by weight, 10-30 parts of nano-aluminum sol, 8-20 parts of a surfactant, 3-8 parts of a polyvinyl alcohol resin, 20-60 parts of an acrylic polymer, and 25-75 parts of water; the raw material of the acrylic polymer comprises an unsaturated carboxylic acid monomer, which accounts for 4.3-18.5% of the total weight of the polymerized monomers of the acrylic polymer; the carboxyl-containing acrylic polymer has a strong interaction with the hydroxyl groups in the vinyl alcohol resin, the surfactant, and the nano-aluminum sol, so that the prepared dripping agent not only has good hydrophilicity and adhesion properties, but also the formed film layer has strong cohesion, thereby providing the dripping agent with a long-lasting dripping effect.

[0033] 2. Furthermore, a cross-linking monomer is also used in the raw materials of the acrylic polymer, and the type and amount of the cross-linking monomer are prioritized to further improve the adhesion performance of the acrylic polymer. At the same time, it has a strong interaction with the vinyl alcohol resin, surfactant and nano-aluminum sol, further improving the long-term dripping effect of the long-acting dripping agent.

[0034] 3. Furthermore, the long-acting dripping agent also includes a persulfate initiator and terminal hydroxyl polybutadiene. By using the terminal hydroxyl polybutadiene and the persulfate initiator, under the action of the initiator, the terminal hydroxyl polybutadiene can undergo a polymerization reaction with the unsaturated bonds in the acrylic polymer, so that the long-acting dripping agent forms a film layer with a body structure, which can improve the cross-linking density, cohesion and adhesion performance, and further improve the long-term dripping effect of the long-acting dripping agent. DETAILED DESCRIPTION

[0035] raw material

[0036] Polyvinyl alcohol resin (polyvinyl alcohol 2488, active ingredient content 99%, melting point: 230-240°C), sodium alginate (food grade, implementation standard: national standard, active ingredient content 99%, white powder particles),

[0037] Nano-aluminum sol (nano-aluminum sol: solid content 25%, particle size 30nm), hydroxyl-terminated polybutadiene (hydroxyl value: 0.50mmol / g, water mass fraction 0.01%, number average molecular weight 40000).

[0038] Preparation examples of intermediates

[0039] Preparation Example 1: An acrylic acid polymer, using raw materials as shown in Table 1, and its preparation process is as follows:

[0040] Preparation of aqueous primer: Add 55 wt% water, 10 wt% emulsifier and 10 wt% unsaturated carboxylic acid into the aqueous phase tank and mix them evenly to prepare the aqueous primer for later use.

[0041] Preparation of aqueous phase dropwise feed: Pour the remaining water, the remaining emulsifier and the remaining unsaturated carboxylic acid into the aqueous phase tank and stir and mix to prepare the aqueous phase dropwise feed for later use.

[0042] Preparation of oil phase material: uniformly mix the hard monomer, soft monomer, crosslinking monomer and divinyl-1,4-butanediol ether in the acrylic polymer to prepare the oil phase material, which is set aside;

[0043] Emulsion polymerization: The reactor was evacuated to below -0.085 MPa, all the aqueous phase primer and 5 wt% of the oil phase were added, and the temperature was raised to 70°C (in other embodiments, the temperature could be raised to any temperature between 65°C and 75°C) under stirring conditions of 200 r / min (the speed could be adjusted within the range of 40-500 r / min according to actual production). 30% of the initiator was added, and the temperature was raised to 75°C under stirring conditions of 200 r / min (the speed could be adjusted within the range of 40-500 r / min according to actual production). Heat, control the temperature at 82° C., react for 20 minutes, then start dropwise addition of the aqueous phase feed, the remaining oil phase feed, and the remaining initiator, and complete the addition within 5 hours (in other embodiments, the addition can be completed within 3-6 hours), and keep the temperature at 82° C. for 1.5 hours under stirring at 200 rpm. After the insulation is completed, transfer the mixture to a degassing kettle, adjust the pH to 6.5±0.5 with sodium hydroxide, and then degas. Filter the material through a 200-mesh filter (in other embodiments, a 150-300-mesh filter can be used to filter) to prepare an acrylic polymer.

[0044] Preparation Examples 2 to 5 are acrylic polymers, which differ from Preparation Example 1 in that the types of raw materials, raw material weights, and preparation process parameter settings are different, as shown in Table 1.

[0045] Table 1. Raw material types, raw material weights, and preparation process parameter settings for acrylic acid polymers prepared in Preparation Examples 1 to 5.

[0046]

[0047]

[0048] Preparation Example 6, an acrylic polymer, differs from Preparation Example 1 in that the crosslinking monomers are hydroxyethyl acrylate and N-hydroxymethyl acrylamide in a mass ratio of 1:2.

[0049] Preparation Example 7, an acrylic polymer, differs from Preparation Example 1 in that the crosslinking monomers are hydroxyethyl acrylate and N-hydroxymethyl acrylamide in a mass ratio of 1:3.

[0050] Preparation Example 8, an acrylic polymer, differs from Preparation Example 1 in that the cross-linking monomers are hydroxypropyl methacrylate and N-hydroxymethyl acrylamide in a mass ratio of 1:3.

[0051] Preparation Example 9, an acrylic polymer, differs from Preparation Example 1 in that the cross-linking monomers are hydroxypropyl methacrylate and diacetone acrylamide in a mass ratio of 1:3.

[0052] Preparation Example 10, an acrylic polymer, differs from Preparation Example 1 in that the crosslinking monomers are hydroxyethyl acrylate and N-hydroxymethyl acrylamide in a mass ratio of 0.5:1.

[0053] Preparation Example 11, an acrylic polymer, differs from Preparation Example 1 in that the crosslinking monomer is hydroxyethyl acrylate.

[0054] Preparation Example 12 is an acrylic polymer, which differs from Preparation Example 1 in that no cross-linking monomer is used.

[0055] Preparation Example 13, an acrylic polymer, is different from Preparation Example 12 in that the raw material of the acrylic polymer further includes 5 kg of divinyl-1,4-butanediol ether.

[0056] Preparation Example 14, an acrylic polymer, is different from Preparation Example 12 in that the raw material of the acrylic polymer further includes 1 kg of divinyl-1,4-butanediol ether.

[0057] Example

[0058] Example 1, a long-acting dripping agent, using raw materials as shown in Table 2, and its preparation process is as follows:

[0059] Preparation of the first mixture: Add a surfactant and nano-aluminum sol (nano-aluminum sol: solid content 20%, particle size 10nm) into a stirring kettle, stir and mix for 15 minutes under constant temperature conditions to prepare the first mixture.

[0060] Preparation of the second mixture: polyvinyl alcohol resin and water were stirred and mixed at a constant temperature for 40 minutes, and then acrylic acid polymer was added to prepare a second mixed solution.

[0061] Preparation of long-acting dripping agent: After adding the second mixed liquid to the first mixture, stirring and mixing for 30 minutes under constant temperature conditions to prepare a long-acting dripping agent.

[0062] In this embodiment, the constant temperature is set to 40° C. and the stirring speed is set to 500 r / min.

[0063] Examples 2 to 3 are long-acting dripping agents, which differ from Example 1 in that the types of raw materials, weights of raw materials and preparation process settings are different, as shown in Table 2.

[0064] Table 2. List of raw material types, raw material weights and preparation process parameters used in the long-acting dripping preparations of Examples 1 to 3

[0065]

[0066]

[0067] Examples 4 to 14 are long-acting dripping agents, which differ from Example 1 in that the acrylic acid polymers are the acrylic acid polymers of Preparation Examples 4 to 14, respectively.

[0068] Example 15 is a long-acting dripping agent, which differs from Example 12 in that the long-acting dripping agent further includes 0.001 kg of ammonium persulfate initiator and 1 kg of hydroxy-terminated polybutadiene.

[0069] Example 16 is a long-acting dripping agent. The difference from Example 12 is that the long-acting dripping agent further includes 0.01 kg of potassium persulfate initiator and 3 kg of terminal hydroxyl polybutadiene.

[0070] Example 17 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:1.5:1.

[0071] Example 18 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:0.8:1.

[0072] Example 19 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:0.5:1.

[0073] Example 20 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:2:1.

[0074] Example 21 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate, oleic acid and sodium alginate in a mass ratio of 1:1.5:1.

[0075] Example 22 is a long-acting dripping agent, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate and sodium alginate in a mass ratio of 1:1.

[0076] Example 23 is a long-acting drip preparation, which differs from Example 15 in that the surfactant is a composition of sorbitan dodecanoate and sodium ricinoleate sulfate in a mass ratio of 1:1.5.

[0077] Example 24 is a long-acting dripping agent, which differs from Example 12 in that the surfactant is a composition of sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate in a mass ratio of 1:1.5:1.

[0078] Comparative Example

[0079] Comparative Example 1 is a long-lasting dripping agent, which differs from Example 12 in that no unsaturated carboxylic acid monomer is used in the acrylic polymer.

[0080] Comparative Example 2 is a long-acting dripping agent, which differs from Example 12 in that no acrylic acid polymer is used.

[0081] Comparative Example 3 is a long-lasting dripping agent, which differs from Example 12 in that an equal amount of aqueous polyurethane (solid content 60%, viscosity 500 mPas at 23° C.) is used to replace the acrylic polymer.

[0082] Performance testing

[0083] Test 1: Long-term drip performance

[0084] The film is fixed on a constant temperature water bath at 60℃, with the water surface about 5 cm above the film and the ambient temperature at room temperature (23±2)℃. When the droplet area on the film is ≥30.0%, it is considered to be invalid. The time is recorded, which is called the long-term effect period and serves as a reference for the long-term effect data of the droplet.

[0085] Test 2: Initial dripping performance

[0086] Place the film in a 60°C constant-temperature water bath, approximately 5 cm above the water surface. The ambient temperature is (23±2)°C. Record the time from the start of the test until the first dew droplet accumulates on the inner surface of the film and falls. This is called the initial droplet time. For film thickness ≤ 0.08 mm, the initial droplet time should be ≤ 420 seconds.

[0087] Test 3: Light transmittance and haze

[0088] According to GB / T 2410-2008, the transmittance and haze of the test samples were tested using a transmittance and haze tester. Each sample was measured 10 times and the average value was taken.

[0089] Haze calculation formula: Td = (T4 / T2-T3 / T1)*100

[0090] The formula for calculating light transmittance is: T = T2 / T1*100

[0091] Where: Td-haze (%); T-transmittance (%); T4-scattered light intensity between the tested sample and the instrument (au); T3-light intensity scattered by the tested instrument (au); T2-light intensity transmitted through the sample (au); T1-incident light intensity (au).

[0092] Test samples: The long-acting drip agents of Examples 1 to 24 and Comparative Examples 1 to 3 are respectively evenly coated on a polyethylene base film with a thickness of 0.08 mm to prepare a polyethylene film with a total thickness of 0.12 mm (after the polyethylene base film is coated with the long-acting drip agent, it is heated at a temperature of 95±10°C for 30±10 minutes); the polyethylene film prepared using the long-acting drip agents of Examples 1 to 24 is the example sample; the polyethylene film prepared using the long-acting drip agents of Comparative Examples 1 to 3 is the comparative sample.

[0093] Test results: For the test results of the long-lasting period, light transmittance and haze of the polyethylene films prepared using the long-lasting drip agents of Examples 1 to 24 and Comparative Examples 1 to 3, refer to Table 3.

[0094] Table 3. Test results of long-term effect, light transmittance and haze of polyethylene films prepared using the long-term dripping agents of Examples 1 to 24 and Comparative Examples 1 to 3

[0095] distinguish Long-term effect / d Initial drip time / s Transmittance / % Haze / % Example 1 25 302 95.6 15.6 Example 2 26 306 93.4 15.7 Example 3 23 295 93.8 15.4 Example 4 18 287 92.1 16.8 Example 5 19 301 92.3 17.9 Example 6 29 328 96.8 13.4 Example 7 30 330 97.2 13.7 Example 8 26 308 95.1 15.7 Example 9 25 305 95.0 15.9 Example 10 27 313 95.7 15.4 Example 11 25 304 95.3 15.8 Example 12 16 264 95.1 15.7 Example 13 24 270 95.2 15.7 Example 14 23 271 95.3 15.5 Example 15 22 270 95.1 15.4 Example 16 23 273 95.2 15.6 Example 17 31 289 96.8 14.1 Example 18 32 293 97.1 13.8 Example 19 27 277 95.8 15.1 Example 20 25 281 95.8 14.8 Example 21 28 272 95.1 15.6 Example 22 23 288 95.6 15.5 Example 23 28 272 97.6 17.3 Example 24 19 273 95.3 15.3 Comparative Example 1 13 206 95.0 15.5 Comparative Example 2 10 185 95.1 15.7 Comparative Example 3 8 183 93.6 16.8

[0096] Combining Examples 1 to 24 and Comparative Examples 1 to 3 and Table 3, it can be seen that the long-acting drip agent of Comparative Example 1 has a longer-lasting period and a shorter initial dripping time than Example 12. This may be because the unsaturated carboxylic acid monomer is not used in the acrylic polymer, the hydrophilicity and adhesion performance of the acrylic polymer are reduced, and the interaction between the acrylic polymer and the nano-aluminum sol, the polyvinyl alcohol resin and the surfactant is weakened, and the cohesive force of the film layer formed by the long-acting drip agent is reduced, which leads to a lower long-acting period and an initial dripping time for the long-acting drip agent of Comparative Example 1.

[0097] The long-lasting period and initial dripping time of the long-acting dripping agent in Comparative Example 2 are lower than those in Example 12. This may be because the acrylic polymer is not used, the interaction between the raw materials of the long-acting dripping agent is weakened, and the cohesion and adhesion performance of the film layer formed by the long-acting dripping agent are reduced.

[0098] The long-acting drip agent of Comparative Example 3 has a long-acting period, initial drip time and transparency lower than those of Example 12, and a higher haze than that of Example 12. This may be because the polarity and hydrophilicity of the ether bond in the aqueous polyurethane are lower than the carboxyl group in the acrylic polymer, and the interaction force between the ether bond and other materials is weak, resulting in a shorter long-acting period and initial drip time; and compared with the acrylic polymer, the light transmittance of the polyurethane is poor, resulting in a lower transparency and higher haze of the film layer formed by the prepared long-acting drip agent.

[0099] The long-acting dripping agent of Examples 6 and 7 has a long-acting period, initial dripping time and transmittance higher than that of Examples 1 to 5 and 8 to 12, and the haze of the long-acting dripping agent of Examples 6 and 7 is lower than that of Examples 1 to 5 and 8 to 12, indicating that the use of a cross-linking monomer and the type and amount of a preferred cross-linking monomer in the acrylic polymer in the long-acting dripping agent further improves the long-acting period, initial dripping time and transmittance of the prepared long-acting dripping agent and reduces the haze; this may be because hydroxyethyl acrylate contains fewer shorter alkyl chains, and the end of the alkyl chain is a hydrophilic hydroxyl group, and the side chain contains an ester group; N-hydroxymethyl acrylamide The side chains are relatively short, the ends of the side chains are hydroxyl groups, and the side chains contain ketone groups and amino groups, so that the prepared acrylic polymers have strong interaction with each other, and have strong interaction with the long-lasting drip agent and other raw materials. On the one hand, the cohesion of the long-lasting drip agent in forming a film layer on the polyethylene film is improved, and on the other hand, the adhesion and hydrophilicity of the film layer formed on the polyethylene film are improved; also because hydroxyethyl acrylate and N-hydroxymethyl acrylamide do not contain long side chains, the prepared acrylic polymer has better flow properties, making the film layer formed by the prepared long-lasting drip agent more uniform, thereby improving the transmittance of the long-lasting drip agent and reducing the haze.

[0100] The long-acting dripping agent of Example 15 and Example 16 has a longer long-acting period than that of Example 12, indicating that the use of divinyl-1,4-butanediol ether in the raw material of the acrylic polymer improves the long-acting period of the long-acting dripping agent; this may be because divinyl-1,4-butanediol ether contains divinyl, and divinyl-1,4-butanediol ether participates in the polymerization of the acrylic polymer, so that the long-acting dripping agent forms a film layer with a network structure, thereby improving the cohesive force and thereby improving the long-acting period of the long-acting dripping agent.

[0101] The long-acting drip agent of Example 17 and Example 18 has a longer-lasting period, an initial dripping time, and a transmittance than that of Example 15 and Examples 19 to 24; the haze of the long-acting drip agent of Example 17 and Example 18 is lower than that of Example 12, Example 15, and Examples 19 to 24; this indicates that the use of a composition of sorbitan dodecanoate, oleic acid, and sodium alginate in the surfactant, optimizing its dosage, and combining it with a persulfate initiator and a terminal hydroxyl polybutadiene further improves the long-acting drip agent's long-acting period, an initial dripping time, and a transmittance, and reduces the haze; this may be because sodium ricinoleate sulfate and sorbitan dodecanoate have more hydrophilic groups and long alkyl chains, which can better promote the emulsification and dispersion effect of the long-acting drip agent, thereby improving Light transmittance reduces haze; sodium alginate has more hydrophilic groups, which improves the dripping effect and prolongs the initial dripping time; the molecular structure of sodium ricinoleate sulfate contains carbon-carbon double bonds. During the film-forming process, under the action of the initiator, it can undergo polymerization reaction with the unsaturated bonds in raw materials such as hydroxypolybutadiene and acrylic polymer, thereby improving the cross-linking density, cohesion and adhesion performance of the film layer formed by the long-lasting dripping agent, and reducing the migration and loss of the emulsifier during use; when the long-lasting dripping agent uses persulfate initiator and terminal hydroxyl polybutadiene, the surfactant uses sorbitan dodecanoate, sodium ricinoleate sulfate and sodium alginate, and their dosage is optimized, which further improves the long-lasting period, initial dripping time and light transmittance of the long-lasting dripping agent and reduces the haze.

[0102] The long-acting dripping agent of Example 21 has a longer-lasting period, initial dripping time, and light transmittance than Example 17, and a higher haze than Example 17. This may be because, compared with sodium ricinoleate sulfate, oleic acid has fewer hydrophilic groups in its structure and has a poorer emulsification effect, resulting in a shorter long-acting period and initial dripping time, a decrease in light transmittance, and an increase in haze.

[0103] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A long-acting dripping agent, characterized in that The raw materials of the acrylic polymer include, by weight, 10-30 parts of nano-aluminum sol, 8-20 parts of surfactant, 3-8 parts of polyvinyl alcohol resin, 20-60 parts of acrylic polymer and 25-75 parts of water; the raw materials of the acrylic polymer include unsaturated carboxylic acid monomer, and the unsaturated carboxylic acid monomer accounts for 4.3-18.5% of the total weight of the polymerized monomers of the acrylic polymer; the raw materials of the acrylic polymer include, by weight, 80-120 parts of water, 1-5 parts of emulsifier, 50-76 parts of soft monomer, 24-50 parts of hard monomer, 5-25 parts of unsaturated carboxylic acid monomer, and 0.3-1.5 parts of polymerization initiator. , 8-15 parts by mass of a cross-linking monomer, and 1-5 parts by mass of divinyl-1,4-butanediol ether; the initiator is persulfate, and the reaction temperature is 80-95°C; the cross-linking monomer is hydroxyethyl acrylate and N-hydroxymethyl acrylamide in a mass ratio of 1:(2-3); the weight ratio of the hard monomer to the soft monomer in the acrylic polymer is (0.32-1):1; the unsaturated carboxylic acid monomer is at least one of acrylic acid, fumaric acid, methacrylic acid, itaconic acid, and maleic acid; the surfactant is a composition of sorbitan lauryl ester, sodium ricinoleate sulfate, and sodium alginate in a mass ratio of 1:(0.8-1.5):

1.

2. A long-acting dripping agent according to claim 1, characterized in that The long-acting dripping agent further comprises 0.001-0.01 parts by mass of a persulfate initiator and 1-3 parts by mass of hydroxyl-terminated polybutadiene.

3. A method for producing the long-acting dripping preparation according to any one of claims 1 to 2, characterized in that the preparation process is as follows: The surfactant and the nano-aluminum sol are stirred and mixed to prepare a first mixture; The polyvinyl alcohol resin, the acrylic acid polymer and water are stirred and mixed to prepare a second mixed solution; The first mixture is added to the second mixed liquid and stirred to prepare a long-acting dripping agent.

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