Mulching film raw material composition, preparation method thereof and mulching film

Abstract

The invention relates to a mulching film raw material composition, a preparation method thereof and a mulching film, and belongs to the technical field of mulching films. The mulching film raw material composition comprises a copolymer of butylene adipate and butylene terephthalate, first polypropylene carbonate and shading master batch, and the shading master batch comprises second polypropylene carbonate and carbon black. According to the mulching film raw material composition provided by the embodiment of the invention, the mulching film has good mechanical properties, moisture preservation performance and relatively long service life.

Description

Technical Field

[0001] The present application relates to the technical field of ground films, and in particular to a ground film raw material composition, a preparation method thereof, and a ground film. Background Art

[0002] Ground film is a material used to cover the surface of the soil. In the process of crop cultivation, ground film can play a role in moisture conservation, heat preservation, weed control, etc., which can improve the growth environment of crops and increase the yield and quality of crops. Therefore, ground film has become an indispensable product for large-scale crop cultivation. With the widespread application of ground film in crop cultivation, the requirements for its performance are getting higher and higher. At present, ground film is used in the cultivation of thermophilic crops (such as tobacco crops, etc.), and there is still the problem that the mechanical properties, moisture conservation performance and service life cannot meet the growth requirements of thermophilic crops. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the embodiments of the present application includes providing a ground film raw material composition, a preparation method thereof and a ground film, so as to improve the technical problem that the mechanical properties, moisture retention properties and service life of the ground film cannot meet the growth requirements of thermophilic crops.

[0004] In a first aspect, an embodiment of the present application provides a ground film raw material composition, which includes a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch includes a second polypropylene carbonate and carbon black.

[0005] The mulch film composition provided in the embodiment of the present application, by taking the copolymer of butylene adipate and butylene terephthalate as the main material, compounding the first polypropylene carbonate and the shading masterbatch can make the mulch film have good mechanical properties, moisture retention performance and a long service life, wherein the shading masterbatch is based on the second polypropylene carbonate and compounded with carbon black, so that the processing temperature of the shading masterbatch can be reduced, so that the components in the shading masterbatch are evenly dispersed and the second polypropylene carbonate is reduced in the probability of degradation during thermal processing, which can help to extend the service life of the mulch film. And the shading masterbatch can cooperate with other components in the mulch film raw material composition to improve the melt strength of the mulch film, so that the processing stability is improved, thereby further improving the mechanical properties and service life of the mulch film. Therefore, the mulch film raw material composition provided in the embodiment of the present application can make the mulch film have good mechanical properties, moisture retention performance and a long service life.

[0006] In some embodiments of the present application, based on 100 parts by weight of the light-shielding masterbatch, the second polypropylene carbonate is 50 parts to 70 parts, and the carbon black is 20 parts to 40 parts.

[0007] In some embodiments of the present application, the first polypropylene carbonate satisfies one or more of the following conditions:

[0008] (I) the number average molecular weight of the first polypropylene carbonate is 50000 g / mol to 100000 g / mol;

[0009] (II) the melt index of the first polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000;

[0010] And / or, the second polypropylene carbonate satisfies one or more of the following conditions:

[0011] (I) the number average molecular weight of the second polypropylene carbonate is 50000 g / mol to 100000 g / mol;

[0012] (II) The melt index of the second polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000.

[0013] In some embodiments of the present application, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (1.25-4):1;

[0014] Optionally, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (2-4):1.

[0015] In some embodiments of the present application, the filler includes modified nano calcium carbonate;

[0016] Optionally, the modified nano-calcium carbonate includes nano-calcium carbonate modified by a coupling agent;

[0017] Optionally, the coupling agent includes one or more of a borate coupling agent, a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent.

[0018] In some embodiments of the present application, the ground film raw material composition includes, by weight:

[0019] Copolymer of butylene adipate and butylene terephthalate, 50 to 80 parts;

[0020] First polypropylene carbonate, 20 to 40 parts;

[0021] Light-shielding masterbatch, 4 to 8 parts.

[0022] Optionally, the ground film raw material composition further comprises, by weight:

[0023] Filler, 5 to 25 parts;

[0024] Antioxidant, 0.3 to 1 part;

[0025] Lubricant, 0.3 to 1.5 parts;

[0026] Compatibilizer, 0.2 to 2 parts.

[0027] In some embodiments of the present application, the copolymer of butylene adipate and butylene terephthalate satisfies one or more of the following conditions:

[0028] (I) The number average molecular weight of the copolymer is 70000 g / mol to 120000 g / mol;

[0029] (II) The melt index of the copolymer is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000;

[0030] (III) The terminal carboxyl group concentration in the copolymer is less than or equal to 15 mol / t.

[0031] In a second aspect, the present application embodiment provides a method for preparing the mulch film raw material composition according to the first aspect of the present application, comprising:

[0032] Providing raw materials, the raw materials comprising a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch comprises a second polypropylene carbonate and carbon black;

[0033] The raw materials are stirred and mixed, and then melt-granulated to obtain a ground film raw material composition.

[0034] In some embodiments of the present application, the preparation method of the light-shielding masterbatch includes:

[0035] The second polypropylene carbonate and carbon black are stirred and mixed, and melt-granulated at 90° C. to 130° C. to obtain a light-shielding masterbatch with a moisture content of less than 500 ppm.

[0036] In a third aspect, an embodiment of the present application provides a ground film, which is prepared using the ground film raw material composition of the first aspect of the present application and / or the ground film raw material composition prepared by the preparation method of the second aspect of the present application; optionally, the ground film includes a tobacco ground film. DETAILED DESCRIPTION

[0037] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0038] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0039] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0040] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0041] In a first aspect, an embodiment of the present application provides a ground film raw material composition, which includes a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch includes a second polypropylene carbonate and carbon black.

[0042] The mulch film composition provided in the embodiment of the present application can make the mulch film have good mechanical properties, moisture retention properties and a long service life by using a copolymer of butylene adipate and butylene terephthalate (English name: Poly (butyleneadipate-co-terephthalate), abbreviated as PBAT) as the main material, compounding the first polypropylene carbonate (English name of polypropylene carbonate: Poly (propylene carbonate), abbreviated as PPC) and the shading masterbatch, wherein the shading masterbatch uses the second polypropylene carbonate as the base material and is compounded with carbon black, which can reduce the processing temperature of the shading masterbatch, make the components in the shading masterbatch disperse evenly, and reduce the probability of degradation of the second polypropylene carbonate during thermal processing, which can help to extend the service life of the mulch film. Moreover, the shading masterbatch can synergistically improve the melt strength of the mulch film with other components in the mulch film raw material composition, so that the processing stability is improved, thereby further enhancing the mechanical properties and service life of the mulch film. Therefore, the ground film raw material composition provided in the embodiments of the present application can make the ground film have good mechanical properties, moisture retention properties and a long service life.

[0043] In the embodiments of the present application, the components of the sunshade masterbatch have appropriate weight fractions, which can be beneficial to improving the mechanical properties and service life of the ground film.

[0044] In some embodiments of the present application, based on 100 parts by weight of the light-shielding masterbatch, the second polypropylene carbonate is 50 parts to 70 parts, and the carbon black is 20 parts to 40 parts.

[0045] In the above embodiment, based on 100 parts by weight of the shading masterbatch, the weight percentage of the second polypropylene carbonate is set within the above range, which can further help the ground film have a suitable amount of water vapor transmittance, so that it has good moisture retention performance. The weight percentage of carbon black is set within the above range, which can help improve the weed suppression performance of the ground film and help improve the yield and quality of crops covered by the ground film. Moreover, the weight percentages of the second polypropylene carbonate and carbon black are respectively set within the above ranges, which can also help the shading masterbatch and other components in the ground film raw material composition to work synergistically, further improving the mechanical properties and service life of the ground film.

[0046] Exemplarily, the second polypropylene carbonate can be, but is not limited to, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, or a range consisting of any two of the above values. Carbon black can be, but is not limited to, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, or a range consisting of any two of the above values.

[0047] In addition, additives in appropriate weight proportions may be added to the light-shielding masterbatch to improve its processing properties.

[0048] In some embodiments of the present application, based on 100 parts by weight of the light-shielding masterbatch, the light-shielding masterbatch further includes: 50 to 70 parts of a second polypropylene carbonate, 20 to 40 parts of carbon black, and 1 to 10 parts of additives.

[0049] For example, the additives may include one or more of a lubricant, an antioxidant, and a light stabilizer, and the additives may be any lubricant, antioxidant, and light stabilizer known in the art for use in masterbatches.

[0050] In some embodiments of the present application, the number average molecular weight of the first polypropylene carbonate is 50,000 g / mol to 100,000 g / mol.

[0051] Herein, the number average molecular weight has a well-known meaning in the art, and can be measured using instruments and methods well known in the art, such as high temperature gel permeation chromatography (abbreviated as high temperature GPC).

[0052] In the above embodiment, the number average molecular weight of the first polypropylene carbonate is within the above range, which can make the ground film have higher mechanical properties and good moisture retention performance.

[0053] Exemplarily, the number average molecular weight of the first polypropylene carbonate can be, but is not limited to, 50,000 g / mol, 55,000 g / mol, 60,000 g / mol, 65,000 g / mol, 70,000 g / mol, 75,000 g / mol, 80,000 g / mol, 85,000 g / mol, 90,000 g / mol, 95,000 g / mol, 100,000 g / mol, or a range consisting of any two of the foregoing values.

[0054] In some embodiments of the present application, the melt index of the first polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and a load of 2.16 kg according to GB / T3682-2000.

[0055] Herein, the melt index refers to an index indicating the fluidity of the first polypropylene carbonate, and is expressed by the amount of the first polypropylene carbonate extruded per 10 minutes through an opening (nozzle) provided at the bottom of a cylindrical container heated by a heater after pressurizing a given amount of the first polypropylene carbonate in a container under a predetermined load (e.g., 2.16 kg) at a predetermined temperature (e.g., 190° C.), and the unit is g / 10 min. The above melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000.

[0056] In the above embodiment, the melt index of the first polypropylene carbonate is within the above range, which can help the ground film raw material composition to be processed and molded into a ground film, and make the ground film have higher mechanical properties.

[0057] Exemplarily, the melt index of the first polypropylene carbonate can be, but is not limited to, 2g / 10min, 2.1g / 10min, 2.2g / 10min, 2.3g / 10min, 2.4g / 10min, 2.5g / 10min, 2.6g / 10min, 2.7g / 10min, 2.8g / 10min, 2.9g / 10min, 3g / 10min, 3.1g / 10min, 3.2g / 10min, 3.3g / 10min, 3.4g / 10min, 3.5g / 10min, 3.6g / 10min, 3.7g / 10min, 3.8g / 10min, 3.9g / 10min, 4g / 10min or a range consisting of any two of the above values.

[0058] In some embodiments of the present application, the second polypropylene carbonate is the same as the first polypropylene carbonate, which can be understood as the second polypropylene carbonate and the first polypropylene carbonate are the same material. Then the second polypropylene carbonate also satisfies one or more of the following conditions:

[0059] (I) the number average molecular weight of the second polypropylene carbonate is 50000 g / mol to 100000 g / mol;

[0060] (II) The melt index of the second polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000.

[0061] In the embodiments of the present application, the mechanical properties of the ground film can be further improved and the ground film can have a suitable water vapor permeability by adjusting the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate.

[0062] In some embodiments of the present application, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (1.25-4):1.

[0063] In some optional embodiments of the present application, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (2-4):1.

[0064] In the above embodiment, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is within the above range, which can make the ground film have higher mechanical properties, good moisture retention performance and service life.

[0065] Exemplarily, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate may be, but is not limited to, 1.25:1, 1.3:1, 1.35:1, 1.4:1, 1.45:1, 1.5:1, 1.55:1, 1.6:1, 1.65:1, 1.7:1, 1.75:1, 1.8:1, 1.85:1, 1.9:1, 1.95:1, 2:1, 2.05:1, 2.1:1, 2.15:1, 2.2:1, 2.25:1, 2.3:1, 2.35:1. :1, 2.4:1, 2.45:1, 2.5:1, 2.55:1, 2.6:1, 2.65:1, 2.7:1, 2.75:1, 2.8:1, 2.85:1, 2.9:1, 2.95:1, 3:1, 3.05:1, 3.1:1, 3.15:1, 3.2:1, 3.25:1, 3.3:1, 3.35:1, 3.4:1, 3.45:1, 3.5:1, 3.55:1, 3.6:1, 3.65:1, 3.7:1, 3.75:1, 3.8:1, 3.85:1, 3.9:1, 3.95:1, 4:1, etc.

[0066] In some embodiments of the present application, the ground film raw material composition further includes a filler.

[0067] Further, the filler includes modified nano-calcium carbonate; optionally, the modified nano-calcium carbonate includes nano-calcium carbonate modified by a coupling agent; further, optionally, the coupling agent includes one or more of a borate coupling agent, a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

[0068] In the above embodiments, the coupling agent-modified nano calcium carbonate has good dispersibility, good impact strength, toughness and other properties, and also has good hydrolysis resistance and thermal stability, which can help improve the processing performance and mechanical properties of the ground film.

[0069] In some embodiments of the present application, the ground film raw material composition includes, by weight:

[0070] Copolymer of butylene adipate and butylene terephthalate, 50 to 80 parts;

[0071] First polypropylene carbonate, 20 to 40 parts;

[0072] Light-shielding masterbatch, 4 to 8 parts.

[0073] Furthermore, additives may be added to the ground film raw material composition to further improve the aging resistance, processing performance, compatibility and other properties.

[0074] In some embodiments of the present application, the above-mentioned auxiliary agent includes, by weight:

[0075] Filler, 5 to 25 parts;

[0076] Antioxidant, 0.3 to 1 part;

[0077] Lubricant, 0.3 to 1.5 parts;

[0078] Compatibilizer, 0.2 to 2 parts.

[0079] In the above embodiment, the weight percentage of PBAT is set within the above range, which can help improve the mechanical properties of the ground film. Compounding the weight percentage of PPC can make the ground film have good mechanical properties and degradation properties while also having a suitable water vapor permeability, so that the ground film has good moisture retention performance. The weight percentage of the shading masterbatch is set within the above range, which can synergize with other components in the ground film raw material composition to help the ground film have good mechanical properties and a good service life. The weight percentage of the filler is set within the above range, and it can also cooperate with PBAT and PPC to improve the mechanical properties and processing properties of the ground film.

[0080] In addition, when the weight fraction of the antioxidant is set within the above range, the oxidation process of the plastic film can be delayed, thereby further improving the anti-aging performance of the plastic film and extending its service life. When the weight fraction of the lubricant is set within the above range, it can contribute to the processing and molding of the plastic film. When the compatibilizer is set within the above range, it can contribute to improving the compatibility between the components in the plastic film raw material composition and the processing performance of the plastic film.

[0081] Exemplarily, the weight fraction of PBAT can be, but is not limited to, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, or the range of values composed of any two of the above values.

[0082] The weight fraction of the first poly(propylene carbonate) can be, but is not limited to, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, or the range of values composed of any two of the above values.

[0083] The weight fraction of the filler can be, but is not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or the range of values composed of any two of the above values.

[0084] The weight fraction of the masterbatch for light shielding can be, but is not limited to, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, or the range of values composed of any two of the above values.

[0085] The weight fraction of the antioxidant can be, but is not limited to, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, or the range of values composed of any two of the above values.

[0086] The weight fraction of the lubricant can be, but is not limited to, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, or the range of values composed of any two of the above values.

[0087] The weight proportion of the compatibilizer can be, but is not limited to, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, or a range consisting of any two of the above values.

[0088] In some embodiments of the present application, the copolymer of butylene adipate and butylene terephthalate satisfies one or more of the following conditions:

[0089] (I) The number average molecular weight of the copolymer is 70000 g / mol to 120000 g / mol;

[0090] (II) The melt index of the copolymer is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000;

[0091] (III) The terminal carboxyl group concentration in the copolymer is less than or equal to 15 mol / t.

[0092] In some embodiments of the present application, the antioxidant includes a primary antioxidant and / or an auxiliary antioxidant, wherein the primary antioxidant includes a phenolic antioxidant, and the auxiliary antioxidant includes one or more of a benzene antioxidant, a phosphite antioxidant, and a thioester antioxidant.

[0093] Exemplarily, the primary antioxidant may include one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester (abbreviated as antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl ester (abbreviated as antioxidant 1076), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (abbreviated as antioxidant 1098), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (abbreviated as antioxidant 330), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazinane-2,4,6-trione (abbreviated as antioxidant 3114) and antioxidant 1798.

[0094] Exemplarily, the auxiliary antioxidant may include tri-tert-butyl-p-hydroxyphenyl propane (referred to as antioxidant 168), bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite (referred to as antioxidant 626), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (referred to as antioxidant 636), bis(2,4-dicumylphenyl) pentaerythritol-diphosphite (referred to as antioxidant 686) and pentaerythritol tetra(3-laurylthiopropionate (referred to as antioxidant 412S).) )

[0095] Exemplarily, the lubricant may include one or more of calcium stearate, pentaerythritol stearate (PETS), N,N'-ethylenebisstearamide (EBS), oleamide, erucamide, polyethylene wax, paraffin wax, and polypropylene wax.

[0096] Exemplarily, the compatibilizer may include one or more of epoxy chain extender, maleic anhydride graft, and peroxide. Specifically, the compatibilizer includes chain extender with model number ADR4370, chain extender with model number ADR4468, dioctyl phthalate (abbreviated as DOP), and the like.

[0097] In a second aspect, the present application embodiment provides a method for preparing the mulch film raw material composition according to the first aspect of the present application, comprising:

[0098] Providing raw materials, the raw materials comprising a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch comprises a second polypropylene carbonate and carbon black;

[0099] The raw materials are stirred and mixed, and then melt-granulated to obtain a ground film raw material composition.

[0100] In the above embodiments, stirring and mixing and melt granulation can be performed using equipment well known in the art. For example, stirring and mixing can be performed using a high-speed mixer, wherein the rotation speed is 300 r / min to 500 r / min and the stirring time is 90 s to 180 s; melt granulation can be performed using a screw extruder, wherein the temperature of the screw extruder is 130° C. to 170° C. and the screw speed is 260 r / min to 320 r / min.

[0101] In some embodiments of the present application, the method for preparing the light-shielding masterbatch includes:

[0102] The second polypropylene carbonate and carbon black are stirred and mixed, and melt-granulated at 90° C. to 130° C. to obtain a light-shielding masterbatch with a moisture content of less than 500 ppm.

[0103] In a third aspect, an embodiment of the present application provides a ground film, which is prepared using the ground film raw material composition of the first aspect of the present application and / or the ground film raw material composition prepared by the preparation method of the second aspect of the present application.

[0104] In the above embodiments, the ground film can be prepared by a blown film method or a cast film method.

[0105] In some specific examples of the present application, the ground film is prepared by a film blowing method, wherein the temperature of the film blowing method is 130°C to 160°C, the blowing ratio is 2.5 to 3.5, the traction ratio is 1.2 to 1.8, and the thickness is 0.007 mm to 0.015 mm.

[0106] In some embodiments of the present application, the mulch film includes a tobacco mulch film.

[0107] 1. Implementation

[0108] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0109] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0110] Example 1

[0111] This embodiment provides a method for preparing a ground film raw material composition, comprising:

[0112] The raw material components are provided according to the following weight proportions: 20 parts of the first PPC, 63.2 parts of PBAT, 10 parts of nano calcium carbonate modified by a borate coupling agent, 5 parts of a light-shielding masterbatch, 0.5 parts of an antioxidant 168, 0.5 parts of an antioxidant 1010, 0.6 parts of polyethylene wax, and 0.2 parts of ADR4468; wherein the second PPC and carbon black (see Table 1) are stirred and mixed, and melt-granulated at 120° C. to obtain a light-shielding masterbatch with a moisture content of less than 500 ppm.

[0113] The above raw material components are added into a high-speed mixer, stirred and mixed at 300 r / min for 120 s. After stirring, the mixed raw materials are put into a twin-screw extruder for melt granulation, wherein the temperatures of each zone of the twin-screw extruder are 130°C, 140°C, 145°C, 150°C, 155°C, 155°C, 155°C, 150°C, 145°C, and 145°C, respectively, and the screw speed is 280 r / min to obtain granules, which are then air-cooled and pelletized through a conveyor belt, and then screened to obtain a mulch raw material composition.

[0114] This embodiment also provides a method for preparing a ground film, comprising:

[0115] The prepared ground film raw material composition was put into the silo of a film blowing machine, and the temperatures of each zone of the film blowing machine were set to 130°C, 140°C, 145°C, 150°C, and 150°C, the blowing ratio was 3.0, the traction ratio was 1.3, and a ground film with a thickness of 0.008mm and a width of 1200mm was obtained by blowing.

[0116] Embodiments 2 to 13

[0117] Compared with Example 1, the differences between Examples 2 to 14 are shown in Table 1.

[0118] Comparative Examples 1 to 3

[0119] Compared with Example 1, the differences of Comparative Examples 1 to 3 are shown in Table 1.

[0120] Table 1 lists the differences in the mulch film raw material compositions in Examples 1 to 14 and Comparative Examples 1 to 3.

[0121]

[0122]

[0123] 2. Test part

[0124] The ground films prepared in the above embodiments and comparative examples were tested for their mechanical properties (including nominal strain at break (transverse and longitudinal) and tensile load (transverse and longitudinal)), water vapor permeability and effective service life according to the test standard method recorded in "GB / T35795-2017 Fully Biodegradable Agricultural Ground Covering Film".

[0125] Specifically, the test method is shown in Table 2.

[0126] Table 2

[0127]

[0128] III. Analysis of test results of various embodiments and comparative examples

[0129] The mulch films of the embodiments and comparative examples were prepared according to the above method, and various properties were measured. The results are shown in Table 3 below.

[0130]

[0131] According to Table 1 and Table 3, by comparing the test results of Examples 1 to 14 and Comparative Examples 1 to 3, it can be seen that the ground film raw material composition provided in the embodiments of the present application can make the ground film have good mechanical properties, moisture retention performance and a long service life.

[0132] Comparing the test results of Examples 1 to 9, it can be seen that when the weight ratio of the weight of PBAT to the total weight of the first PPC and the second PPC is (1.25 to 4): 1, the ground film can have higher mechanical properties, good moisture retention performance and longer service life. Further, when the weight ratio of the weight of PBAT to the total weight of the first PPC and the second PPC is (2 to 4): 1, the mechanical properties of the ground film can be further improved.

[0133] Comparing the test results of Examples 1, 10 and 11, it can be seen that when the number average molecular weight of the first PPC and the second PCC is within the range of 50,000 to 100,000, the mulch film can have higher mechanical properties and good moisture retention performance.

[0134] Comparing the test results of Examples 1, 12 and 13, it can be seen that when the melt index of the first PPC and the second PCC is within the range of 2 g / 10 min to 4 g / 10 min, the ground film can have higher mechanical properties.

[0135] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. A ground film raw material composition, characterized in that: The ground film raw material composition comprises a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch comprises a second polypropylene carbonate and carbon black.

2. The mulch film raw material composition according to claim 1, characterized in that: Based on 100 parts by weight of the light-shielding masterbatch, the second polypropylene carbonate accounts for 50 to 70 parts, and the carbon black accounts for 20 to 40 parts.

3. The ground film raw material composition according to claim 1, characterized in that: The first polypropylene carbonate satisfies one or more of the following conditions: (I) the number average molecular weight of the first polypropylene carbonate is 50000 g / mol to 100000 g / mol; (II) the melt index of the first polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000; And / or, the second polypropylene carbonate satisfies one or more of the following conditions: (I) the number average molecular weight of the second polypropylene carbonate is 50000 g / mol to 100000 g / mol; (II) The melt index of the second polypropylene carbonate is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000.

4. The ground film raw material composition according to any one of claims 1 to 3, characterized in that The weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (1.25-4):1; Optionally, the weight ratio of the copolymer of butylene adipate and butylene terephthalate to the total weight of the first polypropylene carbonate and the second polypropylene carbonate is (2-4):

1.

5. The ground film raw material composition according to claim 1, characterized in that: The ground film raw material composition also includes fillers; Optionally, the filler comprises modified nano calcium carbonate; Optionally, the modified nano-calcium carbonate includes nano-calcium carbonate modified by a coupling agent; Optionally, the coupling agent includes one or more of a borate coupling agent, a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

6. The ground film raw material composition according to claim 5, characterized in that: The ground film raw material composition comprises, by weight: Copolymer of butylene adipate and butylene terephthalate, 50 to 80 parts; First polypropylene carbonate, 20 to 40 parts; Light-shielding masterbatch, 4 to 8 parts; Optionally, the ground film raw material composition further comprises: Filler, 5 to 25 parts; Antioxidant, 0.3 to 1 part; Lubricant, 0.3 to 1.5 parts; Compatibilizer, 0.2 to 2 parts.

7. The ground film raw material composition according to claim 1, characterized in that: The copolymer of butylene adipate and butylene terephthalate satisfies one or more of the following conditions: (I) the number average molecular weight of the copolymer is 70000 g / mol to 120000 g / mol; (II) the melt index of the copolymer is 2 g / 10 min to 4 g / 10 min, and the melt index is measured at 190° C. and 2.16 kg load according to GB / T3682-2000; (III) The terminal carboxyl group concentration in the copolymer is less than or equal to 15 mol / t.

8. A method for preparing the ground film raw material composition according to any one of claims 1 to 7, characterized in that: include: Providing raw materials, the raw materials comprising a copolymer of butylene adipate and butylene terephthalate, a first polypropylene carbonate and a light-shielding masterbatch, wherein the light-shielding masterbatch comprises a second polypropylene carbonate and carbon black; The raw materials are stirred and mixed, and subjected to melt granulation treatment to obtain the ground film raw material composition.

9. The preparation method according to claim 8, characterized in that: The preparation method of the light-shielding masterbatch comprises: The second polypropylene carbonate and carbon black are stirred and mixed, and melt-granulated at 90° C. to 130° C. to obtain a light-shielding masterbatch with a moisture content of less than 500 ppm.

10. A ground film, characterized in that: The mulch film is prepared using the mulch film raw material composition described in any one of claims 1 to 7 and / or the mulch film raw material composition prepared by the preparation method described in any one of claims 8 to 9; Optionally, the mulch film comprises tobacco mulch film.

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