A high-heat-retention light-conversion functional film for rice machine transplanting seedlings and a preparation method thereof

Abstract

The application discloses a high-heat-preservation light-conversion functional film for rice machine transplanting seedlings and a preparation method thereof, and belongs to the technical field of polymer films. The preparation raw materials of the high-heat-preservation light-conversion functional film include a base resin, a rare earth inorganic compound light-conversion agent, hydrotalcite and light calcium carbonate. The functional film is used in combination with a certain amount of common rare earth inorganic compound light-conversion agent, heat-preservation agent hydrotalcite and low-cost light calcium carbonate, and the average particle sizes of the hydrotalcite and the light calcium carbonate are controlled, so that the heat-preservation effect and the light-conversion efficiency of the functional film are obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer film technology, and particularly relates to a high heat-insulating and light-converting functional film for machine-transplanted rice seedlings and its preparation method. Background Technology

[0002] Mechanized rice transplanting is now widely used, which places extremely high demands on the quality of seedlings. Seedlings need to be short and sturdy, with thick stems, well-developed root systems, and tight root systems to ensure smooth transplanting, no missed plantings, and no damage to the seedlings.

[0003] Traditional rice seedling films only provide basic covering and have poor heat retention. Early spring seedlings are easily affected by low temperatures, resulting in uneven emergence and a high rate of seedling rot. Furthermore, they lack spectral control, causing seedlings to become leggy and weak, failing to meet the standards for robust seedlings in machine transplanting. In addition, the few existing light-converting or heat-insulating films are single-function, while films that simultaneously meet both light-converting and heat-insulating requirements are too expensive.

[0004] Therefore, how to provide a low-cost, heat-insulating, light-converting film suitable for machine transplanting of rice seedlings is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention aims to provide a high-heat-insulating and light-converting functional film for rice machine transplanting and its preparation method. This functional film, by combining a certain amount of common rare earth inorganic compound light-converting agent, heat-insulating agent hydrotalcite, and low-cost light calcium carbonate, and by controlling the average particle size of hydrotalcite and light calcium carbonate, significantly improves the heat-insulating effect and light-converting efficiency of the functional film.

[0006] The first objective of this invention is to provide a high-heat-insulating and light-converting functional film for machine-transplanted rice seedlings. By weight, the raw materials for its preparation include 100 parts of matrix resin, 0.5-10 parts of rare earth inorganic compound light-converting agent, 0.5-10 parts of hydrotalcite, and 0.2-3 parts of light calcium carbonate; wherein the average particle size of the hydrotalcite is 0.1-1 μm, and the average particle size of the light calcium carbonate is 2-5 μm.

[0007] In this invention, calcium carbonate itself can reduce the penetration of far-infrared rays and has a certain heat preservation effect. On this basis, on the one hand, the addition of light calcium carbonate with the above-mentioned particle size range is conducive to the dispersion of rare earth inorganic compound light-converting agent and hydrotalcite with the above-mentioned particle size range in the matrix resin, thereby enabling both to exert their effects to a greater extent, promoting the photosynthesis of seedlings and vigorous seedling emergence. On the other hand, the light calcium carbonate with the above-mentioned particle size range can extend the light transmission path in the film by reflecting and dispersing light, which is conducive to the rare earth inorganic compound light-converting agent further exerting its light-converting properties, promoting the photosynthesis of seedlings and vigorous seedling emergence.

[0008] Preferably, the average particle size of the light calcium carbonate is 3.5~5μm, or even 4~5μm. Further controlling the average particle size of the light calcium carbonate within the above range is more conducive to light conversion efficiency.

[0009] Preferably, the rare earth inorganic compound light-converting agent is MS:Eu,Re, wherein M is selected from at least one of Mg, Ca, Sr, and Ba, and Re is selected from at least one of Ce, Dy, Sm, Yb, Tb, Tm, Pr, Nd, Sm, Gd, Er, and Cu. More preferably, the rare earth inorganic compound light-converting agent is a combination of a red light-converting agent (e.g., CaS:Eu,Sm) and a blue light-converting agent (e.g., CaS:Eu,Cu); even more preferably, the mass ratio of the red light-converting agent to the blue light-converting agent is 1:1 to 2.5.

[0010] Preferably, the matrix resin is selected from at least one of LDPE and LLDPE. More preferably, the matrix resin is selected from LDPE and LLDPE. More preferably, the mass ratio of LDPE to LLDPE is 5~40:60~95. More preferably, under conditions of 190°C and a load of 2.16 kg, the melt index of the matrix resin is 0.2~2 g / 10 min.

[0011] Preferably, the raw materials for preparation also include at least one of other inorganic fillers, lubricants, light stabilizers, antioxidants, coupling agents, and anti-dripping and anti-fogging agents.

[0012] More preferably, the other inorganic filler is selected from at least one of talc, mica, kaolin, barium sulfate, zinc sulfide, aluminum sulfide, and calcium sulfide. More preferably, the other inorganic filler is 0.2 to 8 parts.

[0013] More preferably, the lubricant is selected from at least one of paraffin wax, polyethylene wax, stearic acid, calcium stearate, oleamide, and erucamide. More preferably, the lubricant is present in quantities of 0.05 to 2 parts.

[0014] More preferably, the light stabilizer is selected from at least one of light stabilizer 944, light stabilizer 622, light stabilizer 783, and light stabilizer 788. More preferably, the amount of light stabilizer is 0.05 to 2 parts.

[0015] More preferably, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 245, antioxidant 168, and antioxidant 626. More preferably, the antioxidant is present in quantities of 0.05 to 2 parts.

[0016] More preferably, the coupling agent is selected from at least one of silane coupling agents (such as KH-550, KH-560, KH-570, etc.) and titanate coupling agents (such as NDZ-101, TMC-102). More preferably, the coupling agent is in the form of 0.1 to 3 parts.

[0017] More preferably, the anti-drip and anti-fogging agent is selected from at least one of glyceryl monostearate, polyglycerol ester, sorbitan monostearate, sorbitan monooleate, polyoxyethylene sorbitan monooleate, fluorinated surfactant, and silicone surfactant. More preferably, the anti-drip and anti-fogging agent is present in quantities of 0.1 to 3 parts.

[0018] Preferably, the high heat-insulating and light-converting functional film is a single-layer film, a double-layer film, or a multilayer film with three or more layers.

[0019] Preferably, the thickness of the high heat-insulating and light-converting functional film is 0.1~0.2mm.

[0020] The second objective of this invention is to provide a method for preparing the above-mentioned high heat-insulating and light-converting functional thin film, which includes the following steps:

[0021] The mixture of the raw materials is melt-extruded and blown into a film to obtain the high heat-insulating and light-converting functional film.

[0022] Preferably, the rare earth inorganic compound brightening agent, the hydrotalcite, and the light calcium carbonate are mixed and ball-milled before being mixed with the matrix resin. More preferably, the ball-milling time is 10-30 minutes.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The high heat-insulating and light-converting functional film for machine-transplanted rice seedlings of the present invention, in combination with common rare earth inorganic compound light-converting agents, heat-insulating agents hydrotalcite and low-cost light calcium carbonate, improves the heat-insulating effect and light-converting efficiency, which is conducive to promoting the photosynthesis of seedlings and vigorous seedling emergence. Attached Figure Description

[0025] Figure 1 This is a photo taken on the 5th day of rice seedling cultivation using the high heat-insulating and light-converting functional film obtained in Example 4 of the present invention for machine transplanting.

[0026] Figure 2 This is a photograph taken on the 5th day of rice seedling cultivation using the functional film obtained in Comparative Example 1 of the present invention for machine transplanting. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0028] Unless otherwise specified, all raw materials used in this invention are commercially available. The rare earth inorganic compound light-converting agent was obtained from Gansu Rare Earth New Materials Co., Ltd.

[0029] Example 1

[0030] This embodiment provides a high-heat-insulating and light-converting functional film for machine-transplanted rice seedlings. The raw materials, by weight, include: 60 parts LLDPE (MFI=1.0 g / 10 min), 40 parts LDPE (MFI=1.9 g / 10 min), 0.25 parts rare earth inorganic compound light-converting agent CaS:Eu,Sm, 0.25 parts rare earth inorganic compound light-converting agent CaS:Eu,Cu, 0.5 parts hydrotalcite (average particle size 0.1 μm), 0.2 parts light calcium carbonate (average particle size 2 μm), 0.1 parts polyethylene wax, 0.1 parts light stabilizer 788, 0.1 parts antioxidant 1010, 0.1 parts KH-550, and 0.1 parts glyceryl monostearate.

[0031] Its preparation methods include:

[0032] According to the mass proportions, the rare earth inorganic compound light-converting agent, hydrotalcite, and light calcium carbonate are ball-milled for 20 minutes, then premixed with other preparation raw materials and added to a blown film machine. The cylinder temperature is controlled at about 190°C and the blow-up ratio is 2.5:1 to obtain a high heat-insulating light-converting functional film with a film thickness of 0.1 mm.

[0033] Examples 2-10 and Comparative Examples 1-2:

[0034] The raw materials used in the above embodiments and comparative examples are shown in Table 1. The preparation methods are as described in Example 1.

[0035] Table 1: Raw material composition for the preparation of Examples 1-10 and Comparative Examples 1-2

[0036]

[0037] The following are performance tests:

[0038] 1. Mechanical properties: Referring to GB / T 1040.3-2006, the high heat-insulating and light-converting functional films for rice machine transplanting obtained in Examples 1-10 and Comparative Examples 1-2 were cut into Type 2 strips with a width of 25 mm. Their mechanical strength (longitudinal) was tested at a test rate of 500 mm / min, and the unit is MPa. The results are shown in Table 2.

[0039] 2. Light Conversion Efficiency: The light conversion efficiency of the high heat-insulating and light-converting films obtained in Examples 1-10 and Comparative Examples 1-2 for rice machine transplanting seedling cultivation was tested using portable photosynthesis meters at approximately 10:00 am on the 15th day after sowing (sunny day). The units were μmol CO2·m -2 ·s -1 The results are shown in Table 2. A higher photosynthetic rate indicates a higher light conversion efficiency.

[0040] Table 2: Performance of the high heat-insulating and light-converting functional films obtained in Examples 1-10 and Comparative Examples 1-2

[0041]

[0042] 3. Heat preservation: The light conversion efficiency of the high heat preservation and light conversion films obtained in Examples 1-10 and Comparative Examples 1-2 for rice machine transplanting seedling cultivation was used to measure the internal and external temperatures of the different high heat preservation and light conversion films on the 20th day after sowing (sunny day). The internal and external temperatures at 8:00 am, 12:00 am, 2:00 pm, 6:00 pm and 9:00 pm were recorded in °C. The results are shown in Table 3.

[0043] Table 3: Thermal insulation performance of the high thermal insulation and light conversion functional films obtained in Examples 1-10 and Comparative Examples 1-2

[0044]

[0045] As shown in Tables 2 and 3, the high heat-insulating and light-converting functional films obtained in Examples 1 to 10 of the present invention not only meet the mechanical performance requirements of agricultural films, but also have excellent light conversion efficiency and heat-insulating effect, making them suitable for the rice seedling cultivation process of machine transplanting.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.

Claims

1. A high-heat-insulating and light-converting functional film for machine-transplanted rice seedling cultivation, characterized in that, The raw materials for preparation, by weight, include 100 parts of matrix resin, 0.5-10 parts of rare earth inorganic compound light conversion agent, 0.5-10 parts of hydrotalcite and 0.2-3 parts of light calcium carbonate; The average particle size of the hydrotalcite is 0.1~1μm, and the average particle size of the light calcium carbonate is 2~5μm.

2. The high heat-insulating and light-converting functional film according to claim 1, characterized in that, The average particle size of the light calcium carbonate is 3.5~5μm.

3. The high heat-insulating and light-converting functional film according to claim 1, characterized in that, The rare earth inorganic compound light-converting agent is MS:Eu,Re, wherein M is selected from at least one of Mg, Ca, Sr, and Ba, and Re is selected from at least one of Ce, Dy, Sm, Yb, Tb, Tm, Pr, Nd, Sm, Gd, Er, and Cu.

4. The high heat-insulating and light-converting functional film according to claim 3, characterized in that, The rare earth inorganic compound light-converting agent is selected from red light-converting agents and blue light-converting agents with a mass ratio of 1:1 to 2.

5.

5. The high heat-insulating and light-converting functional film according to claim 1, characterized in that, The matrix resin is selected from at least one of LDPE and LLDPE.

6. The high heat-insulating and light-converting functional film according to claim 1, characterized in that, The raw materials used in the preparation also include at least one of other inorganic fillers, lubricants, light stabilizers, antioxidants, coupling agents, and anti-dripping and anti-fogging agents.

7. The high heat-insulating and light-converting functional film according to claim 6, characterized in that, The other inorganic fillers are selected from at least one of talc, mica, kaolin, barium sulfate, zinc sulfide, aluminum sulfide, and calcium sulfide.

8. The high heat-insulating and light-converting functional film according to claim 1, characterized in that, The high heat-insulating and light-converting functional film is a single-layer film, a double-layer film, or a multilayer film with three or more layers; and / or, the thickness of the high heat-insulating and light-converting functional film is 0.1~0.2mm.

9. The method for preparing a high-temperature insulation and light-conversion functional thin film according to any one of claims 1 to 8, characterized in that, Includes the following steps: The mixture of the raw materials is melt-extruded and blown into a film to obtain the high heat-insulating and light-converting functional film.

10. The method for preparing the high heat-insulating and light-converting functional thin film according to claim 9, characterized in that, The rare earth inorganic compound brightening agent, the hydrotalcite and the light calcium carbonate are mixed and ball-milled, and then mixed with the matrix resin.

Images