Resin composition for cotton packaging film as well as preparation method and application of resin composition

Abstract

The invention relates to the field of polyolefin films, and discloses a resin composition for a cotton packaging film as well as a preparation method and application of the resin composition. The resin composition contains LLDPE (Linear Low Density Polyethylene) resin, a light stabilizer, an ultraviolet light crosslinking agent, a nucleating agent, rubber particles with a crosslinking structure and optional auxiliaries, the resin composition comprises the following components in parts by mass relative to 100 parts of LLDPE resin: 0.1 to 0.4 part of a light stabilizer, 0.2 to 0.6 part of rubber particles with a cross-linked structure, 0.2 to 0.6 part of a nucleating agent and 0.3 to 0.8 part of an ultraviolet light cross-linking agent. The obtained film is simple in preparation method, has high strength, puncture resistance, light stability, heat stability, high weather resistance and low cost, is suitable for being used as a cotton packaging film, and has important industrial application value.

Description

Technical Field

[0001] The present invention relates to the field of polyolefin films, and more particularly to a resin composition for cotton packaging film, a preparation method thereof and an application thereof. Background Art

[0002] Cotton packaging film bags are a new type of product. The main raw materials are linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE) and high-density polyethylene (HDPE). At the same time, in order to reduce the shear stress during processing, reduce melt fracture, increase the strength of the film bag, improve its barrier property and weather resistance (different use environments such as high temperature or low temperature), and facilitate the packaging machine to perform heat sealing, cooling and palletizing during operation, etc., it is also necessary to add a small amount of lubricant, anti-sticking agent, barrier agent, opening agent, UV protection additive and antioxidant and other modifiers (collectively referred to as additives). Since cotton packaging needs to ensure weather resistance, high strength, puncture resistance, heat sealing, printability and palletizing, the existing single-layer blown film is difficult to achieve these goals at the same time. Such problems can only be solved by increasing the amount of additives, which ultimately leads to a corresponding increase in film thickness, raw material consumption, and utility consumption under the same quality requirements, and a significant increase in comprehensive costs.

[0003] Therefore, in view of the physical properties required for cotton packaging film, how to provide a single-layer cotton packaging film with high strength, high weather resistance and puncture resistance, reduce the film thickness and reduce costs is a technical problem that needs to be solved at present. Summary of the invention

[0004] In order to solve the above technical problems, the invention provides a resin composition for cotton packaging film, a preparation method and application thereof. The resin composition of the invention, through various types and proportions of additives, makes the single-layer cotton packaging film made of the resin composition have high strength and puncture resistance, light stability, thermal stability and high weather resistance, and has a smaller thickness and low cost under the same mechanical strength, and has important industrial application value.

[0005] The first aspect of the present invention is to provide a resin composition, comprising LLDPE resin, a light stabilizer, an ultraviolet light crosslinking agent, a nucleating agent, rubber particles with a crosslinking structure, and optional auxiliary agents; in parts by mass, relative to 100 parts of the LLDPE resin, the resin composition comprises 0.1-0.4 parts of the light stabilizer, 0.2-0.6 parts of the rubber particles with a crosslinking structure, 0.2-0.6 parts of the nucleating agent, and 0.3-0.8 parts of the ultraviolet light crosslinking agent.

[0006] The resin composition of the invention is suitable for preparing films with different thicknesses for outdoor use, and is particularly suitable for cotton packaging films with a thickness of about 130-180 μm, and has high strength and high weather resistance.

[0007] According to the present invention, the resin composition can be used as a resin composition for cotton packaging film.

[0008] According to the present invention, the nucleating agent can be selected from a wide range. In a preferred embodiment of the present invention, the nucleating agent is selected from at least one of sorbitol derivative nucleating agents, organic carboxylic acid nucleating agents, organic carboxylate nucleating agents, and organic phosphate nucleating agents; preferably,

[0009] The nucleating agent is selected from at least one of nucleating agent NA11, nucleating agent NA21, and nucleating agent 20E.

[0010] In a preferred embodiment of the present invention, the rubber particles have at least one of the following characteristics:

[0011] The average particle size of the cross-linked rubber particles is 0.02 to 2 microns, preferably 0.1 to 1 micron, and more preferably 0.2 to 0.5 microns; and / or,

[0012] The rubber particles with cross-linked structure are spherical; and / or,

[0013] The gel content of the rubber particles having a cross-linked structure is 60 wt % or more, preferably 80 wt % or more.

[0014] In a preferred embodiment of the present invention, the rubber particles are at least one of the following rubber particles having a cross-linked structure: natural rubber, styrene-butadiene rubber, carboxylated styrene-butadiene rubber, nitrile rubber, carboxylated nitrile rubber, chloroprene rubber, polybutadiene, acrylic rubber, styrene-butadiene rubber, isoprene rubber, butyl rubber, ethylene-propylene rubber, polysulfide rubber, acrylate-butadiene rubber, polyurethane rubber or fluororubber, ethylene-vinyl acetate rubber; preferably ethylene-vinyl acetate rubber particles.

[0015] The rubber particles with cross-linked structure described in the present invention can be prepared by the method of patent CN1402752, that is, a rubber latex containing uncross-linked rubber particles with a particle size of 20-2000nm is added with a cross-linking agent such as TMPTA, irradiated by a high-energy ray source, and spray-dried to prepare the rubber particles. The obtained cross-linked rubber particles are easy to disperse and can be used as a carrier to assist the nucleating agent and the light stabilizer to be more evenly dispersed in the matrix resin, thereby significantly improving the comprehensive mechanical properties of the resin composition and meeting the requirements in the cotton packaging process. During the transportation and storage of cotton bales, due to the combined effects of ultraviolet light and heat, the polyethylene molecular chain breaks and a large number of free radicals are generated. At this time, the ultraviolet cross-linking agent in the composition can not only absorb free radicals, but also react with the cross-linked rubber particles to promote the generation of the cross-linked structure, so that the mechanical properties of the composition can be effectively maintained, so that the packaging film can meet the requirements of high strength and high weather resistance during storage and transportation.

[0016] In the present invention, the nucleating agent and the rubber particles having a cross-linked structure may be added to the resin composition as separate raw materials, or a commercial product containing both may be used.

[0017] In another preferred embodiment of the present invention, the rubber particles and the nucleating agent are derived from a resin nucleating agent containing both the rubber particles and the nucleating agent;

[0018] Preferably, the mass ratio of the rubber particles to the nucleating agent in the resin nucleating agent is (3-7): (7-3) and / or,

[0019] Preferably, the resin nucleating agent is selected from at least one of VP101B, VP101C, and VP801E.

[0020] According to the present invention, the nucleating agent and the rubber particles with a cross-linked structure have a synergistic effect with the other components in the present invention and can be uniformly dispersed in the resin matrix. During the UV aging process, because the cross-linking reaction is gradually accelerated and the cross-linking density increases, the uniformly dispersed nucleating agent and rubber particles will compensate for the decrease in crystallinity and crystallization rate caused by cross-linking, and maintain the mechanical properties and good processing properties of the material.

[0021] According to the present invention, the UV crosslinking agent can be selected in a wide range. In a preferred embodiment of the present invention, the UV crosslinking agent is selected from at least one of the crosslinking agents capable of undergoing isocyanate internal crosslinking and / or ketone hydrazine self-crosslinking reactions; preferably at least one of the crosslinking agents capable of undergoing isocyanate internal crosslinking and / or ketone hydrazine room temperature self-crosslinking reactions at room temperature, such as 22-28°C;

[0022] More preferably, the UV crosslinking agent is selected from at least one of trimethylolpropane triacrylate, benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diphenylacetophenone, α,α-dimethoxy-α-phenylacetophenone, α,α-diethoxyacetophenone, α-hydroxyalkylphenone, α-aminoalkylphenone, aromatic acylphosphine oxide, bisbenzoylphenylphosphine oxide, benzophenone, 2,4-dihydroxybenzophenone, thiopropoxythioxanthone and isopropylthioxanthone; more preferably, trimethylolpropane triacrylate (TMPTA).

[0023] In a preferred embodiment of the present invention, the content of the light stabilizer is 0.2-0.4 parts by mass relative to 100 parts of LLDPE resin.

[0024] According to the present invention, the light stabilizer can be selected from a wide range. In a preferred embodiment of the present invention, the light stabilizer is selected from at least one of the following light stabilizers:

[0025] Salicylate light stabilizers, benzoate light stabilizers, benzophenone light stabilizers, benzotriazole light stabilizers, triazine light stabilizers, substituted acrylonitrile light stabilizers, oxamide light stabilizers, organic nickel complex light stabilizers, hindered amine light stabilizers;

[0026] More preferably, the light stabilizer is selected from hindered amine light stabilizers, and more preferably selected from at least one of light stabilizer 944, light stabilizer 362 and light stabilizer 622.

[0027] According to the present invention, the auxiliary agent can be selected from a wide range. In a preferred embodiment of the present invention, the auxiliary agent includes an antioxidant; preferably,

[0028] The antioxidant includes a primary antioxidant and a secondary antioxidant.

[0029] In a more preferred embodiment of the present invention, based on parts by mass, relative to 100 parts of LLDPE resin, the amount of the primary antioxidant is 0.02-0.1 parts; the amount of the secondary antioxidant is 0.02-0.15 parts.

[0030] In a more preferred embodiment of the present invention, the primary antioxidant is a hindered phenol antioxidant, preferably selected from at least one of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.

[0031] In a more preferred embodiment of the present invention, the auxiliary antioxidant is selected from phosphites and / or thioester antioxidants, preferably selected from phosphites, including at least one of tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(octadecyl)pentaerythritol diphosphite, pentaerythritol bis(diphosphite (2,4-tert-butylphenyl) ester, bis(2,6-di-tert-butyl-4-tolyl)pentaerythritol phosphite, tetrakis(2,4-di-tert-butyloctaalkoxy-4,4'-biphenyl) phosphate, and 2,2-ethylenebis(4,6-di-tert-butylphenyl)fluorophosphite.

[0032] The LLDPE resin involved in the present invention is produced by polymerization of ethylene or copolymerization of ethylene and α-olefin, wherein the α-olefin is selected from at least one of butene-1, hexene-1 or octene-1.

[0033] The auxiliary agent of the composition of the present invention may also include at least one auxiliary agent commonly used in plastic processing, and the amount used is a conventional amount, or can be adjusted according to the actual requirements.

[0034] The second aspect of the present invention is to provide a method for preparing the resin composition described in the first aspect, comprising melt blending raw materials including the LLDPE resin, light stabilizer, nucleating agent, ultraviolet crosslinking agent, rubber particles with a crosslinked structure and optional additives to obtain the resin composition; preferably, firstly premixing the raw materials including the LLDPE resin, light stabilizer, nucleating agent, ultraviolet crosslinking agent, rubber particles with a crosslinked structure and optional additives to obtain a premixed composition; and then melt blending the obtained premixed composition to obtain the resin composition.

[0035] The resin composition of the present invention is prepared by melt blending the raw material components including LLDPE resin and the like described above in one step by using a common rubber and plastic blending device using a common melt blending method in rubber and plastic processing.

[0036] During the preparation process, the blending temperature of the materials corresponds to the usual processing temperature of the base polyethylene resin, and should be selected within the range that ensures that the base polyethylene resin is completely melted and does not decompose. According to processing requirements, conventional additives for plastic processing can be added to the blended materials in appropriate amounts. During the blending process, the components can be added to the melt blending equipment at the same time by metering or the like for melt blending; or the components can be pre-mixed uniformly by a general mixing equipment, and then melt blended and extruded once by a rubber-plastic blending equipment to obtain a modified resin composition.

[0037] The rubber and plastic blending equipment used in the preparation method of the present invention can be an open mixer, internal mixer, single screw extruder, twin screw extruder or torque rheometer, etc. The material mixing equipment is selected from mechanical mixing equipment such as high-speed mixers and kneaders commonly used in the art.

[0038] The third aspect of the present invention is to provide a resin composition film, wherein the material of the resin composition film is the resin composition described in the first aspect or the resin composition prepared by the preparation method described in the second aspect; preferably,

[0039] The average thickness of the resin composition film is 0.13-0.18 mm.

[0040] The resin composition film of the present invention has a smaller thickness under the condition of equal mechanical strength, has a higher strength under the condition of equal thickness, and also has higher light stability, higher thermal stability and high weather resistance.

[0041] The fourth aspect of the present invention is to provide a method for preparing the resin composition film described in the third aspect, comprising blow molding the resin composition described in the first aspect or the resin composition prepared by the preparation method described in the second aspect to obtain the resin composition film.

[0042] The method of the invention is simple and easy to implement, has universal applicability, and is easy to realize industrial production.

[0043] The fifth aspect of the present invention is to provide a use of the resin composition film described in the third aspect or the resin composition prepared by the preparation method described in the fourth aspect in the packaging field, preferably in the cotton packaging field.

[0044] In summary, the resin composition involved in the present invention is prepared by a physical blending method for the physical properties required by the cotton packaging film, including LLDPE resin, light stabilizer, ultraviolet light crosslinking agent, nucleating agent, rubber particles with a crosslinked structure, etc., and by optimizing the types and contents of the above additives, a single-layer cotton packaging film is achieved that has high strength and puncture resistance, as well as light stability, thermal stability and high weather resistance, low cost, and important industrial application value.

[0045] The resin composition film of the present invention has a smaller thickness under the condition of equal mechanical strength, has a higher strength under the condition of equal thickness, and also has higher light stability, higher thermal stability and high weather resistance.

[0046] The invention can reduce the thickness of the cotton packaging film, reduce the cost, is easy to promote, and has significant social and economic benefits. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0048] The scope of the present invention is not limited by these embodiments, but is set forth in the appended claims.

[0049] The experimental data in the examples were measured using the following equipment and methods:

[0050] The tensile load and nominal strain at break of the specimens were tested in accordance with the national standard GB / T1040.3-2006. The specimens were type 2, 10 mm wide, 50 mm between the initial markings of the fixtures, and 500 mm / min in test speed (no load). The specimens were stretched until they broke, and the maximum tensile load was measured with an accuracy of 0.01 N. The specimen numbers and sampling directions (horizontal or vertical) were clearly indicated for the prepared specimens.

[0051] The nominal strain at break is calculated as follows:

[0052] ε=ΔL / L×100

[0053] Where:

[0054] ε——nominal strain at fracture, %;

[0055] ΔL——Increment of the distance between fixtures, in millimeters (mm);

[0056] L——The initial distance between the fixtures, in millimeters (mm).

[0057] The test is carried out in accordance with QB / T1130-1991, with a single specimen test and an accuracy of 0.1N.

[0058] The falling dart impact test was carried out according to standard GB / T9639, method B was selected for the experiment, the state adjustment time was 8h, the experimental temperature was 23℃, and the impact damage mass value was obtained.

[0059] In the following examples, 1076 refers to antioxidant 1076 produced by BASF Chemicals; 168 refers to antioxidant 168 produced by BASF Chemicals; 944 refers to light stabilizer 944 produced by Beijing Tiangang Chemicals;

[0060] The cross-linked EVA (ethylene-vinyl acetate) rubber particles produced by the Beijing Institute of Chemical Technology have an average particle size of 0.2 microns and a gel content of 85 wt %; MILIKEN's nucleating agent HPN20E is a polyethylene nucleating agent.

[0061] In the following examples and comparative examples:

[0062] The process of initial mixing and melt blending of materials is as follows: first weigh all materials according to the proportion, perform preliminary mixing in a high-speed mixer for 20 seconds, and then use a twin-screw extruder for melt blending and granulation. The mixing equipment is a Coperion 35 twin-screw extruder with a speed of 200r / min and a temperature setting of 170°C, 180°C, 190°C, 200°C, 200°C, and 200°C; the obtained pellets are placed in a tray and heated at 70°C o degrees in an oven for 4 hours to remove moisture.

[0063] The film was prepared by blow molding: the equipment was a German Colin film blowing machine, the temperatures of each section were set at 160°C, 180°C, 200°C, 210°C, 210°C, 210°C, 210°C, the feed amount was 50%, the winding rate was 2m / min, and the obtained film had a smooth surface, an average width of 22cm, and an average thickness of 140μm.

[0064] The prepared tensile and right-angle tearing specimens need to be subjected to artificial ultraviolet aging comparative experiments. The specific conditions of ultraviolet aging are as follows: refer to GB / T16422.3-2014, the light source is a fluorescent ultraviolet lamp, UV-A340 lamp tube, at a wavelength of 340nm, the irradiance is 0.76W / (m 2 ·nm), and UV irradiation was carried out according to the rule of illumination temperature 60℃, radiation time 8h (bright); condensation temperature 50℃, condensation time 4h (dark), and the irradiation time was 240h, 480h, 720h, and 960h.

[0065] Comparative Examples 1 to 5

[0066] The LLDPE resin 1802 powder provided by Zhenhai Petrochemical was used as the matrix, with a weight of 2000g, and was initially mixed and melt-blended with 0.80g 1076, 1.6g 168, and 8g 944 produced by Beijing Tiangang Chemical. The obtained pellets were blown to prepare films, and tensile and dart impact specimens were prepared as Comparative Example 1. The obtained specimens were subjected to artificial ultraviolet accelerated aging for 240h, 480h, 720h, and 960h, and were marked as Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5, respectively.

[0067] Example 1 to Example 5

[0068] The LLDPE resin 1802 powder provided by Zhenhai Petrochemical was used as the matrix, with a weight of 2000g, and 0.80g 1076, 1.6g 168, 8g 944 produced by Beijing Tiangang Chemical, 4.8g cross-linked EVA rubber particles produced by Beijing Institute of Chemical Research, 11.2g MILIKEN nucleating agent HPN20E, 10g trimethylolpropane triacrylate (TMPTA) of Tianjin Tianjiao Chemical Co., Ltd., the materials were initially mixed and melt blended, and the obtained pellets were used to prepare films by a blow molding method to prepare tensile and dart impact specimens, which are Example 1. The obtained specimens were marked as Example 2, Example 3, Example 4, and Example 5 respectively after artificial ultraviolet accelerated aging for 240h, 480h, 720h, and 960h.

[0069] Example 6 to Example 10

[0070] The LLDPE resin 1802 powder provided by Zhenhai Petrochemical was used as the matrix, with a weight of 2000g, and 0.80g 1076, 1.6g 168, 8g 944 produced by Beijing Tiangang Chemical, 11.2g cross-linked EVA rubber particles produced by Beijing Institute of Chemical Research, 4.8g MILIKEN nucleating agent HPN20E, 15g TMPTA of Tianjin Tianjiao Chemical Co., Ltd., the materials were initially mixed and melt-blended, and the obtained pellets were used to prepare films by a blow molding method to prepare tensile and dart impact specimens, which are Example 6. The obtained specimens were marked as Example 7, Example 8, Example 9, and Example 10 respectively after artificial ultraviolet accelerated aging for 240h, 480h, 720h, and 960h.

[0071] The samples of the embodiments and comparative examples were tested by the aforementioned method, and the test results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] As can be seen from Table 1, the tensile load and dart impact strength of the comparative film samples without the addition of powdered rubber, nucleating agent, TMPTA and other additives before aging are much lower than those of the example samples, indicating that the addition of powdered rubber, TMPTA and nucleating agent can improve the mechanical properties of the resin composition and meet the mechanical property requirements when cotton is packaged.

[0076] The data of comparative samples 1-5 show that as the aging time increases, the tensile load, nominal strain at break, and dart impact damage quality of the comparative samples all decrease significantly. For comparative sample 5 with an aging time of 960h, the tensile load is reduced by about 30%, and the dart impact damage quality is reduced by 23%. This is because a large number of free radicals generated during the aging process significantly destroy the long molecular chains in the polyethylene, shortening the polyethylene molecular chains and reducing its tensile load and dart impact damage quality.

[0077] The data of Examples 1-10 show that after different ratios of nucleating agents, light stabilizers, and TMPTA are used to modify polyethylene resin, as the aging time continues to increase, the tensile load loss rate of the example samples remains at a low level, about 10-15%; its nominal strain at break remains basically unchanged, and the loss rate of the mass of the dart impact damage is also maintained at about 10%. This is because during the addition process, TMPTA will first be evenly dispersed in the resin matrix along with the cross-linked rubber particles and nucleating agents. Since it is a small molecule substance, it will migrate to the resin surface when it is exposed to heat during the ultraviolet aging process of the film, absorb a large number of free radicals generated by the light and heat effects on the surface of the matrix, and the cross-linked structure generated by the reaction compensates for the mechanical loss caused by the breakage of the polyethylene molecular chain. The thickness of cotton packaging film is generally greater than 100μm, so the migration of TMPTA is a slow and long process, which enables it to absorb the free radicals generated in the matrix in a long-term and stable manner. At the same time, the increased degree of cross-linking on the surface of the cotton packaging film can also prevent ultraviolet light from entering the film, effectively protecting the macromolecular chains inside the matrix, thereby helping to maintain the strength of the film in high heat and high ultraviolet environments, so that it can meet the storage and transportation needs after cotton packaging.

[0078] The LLDPE resin 1802 in the above embodiment is replaced by other types of LLDPE resin, other types of rubber particles recorded in the present invention, other types of nucleating agents recorded in the present invention, other types of light stabilizers recorded in the present invention, and other types of ultraviolet cross-linking agents recorded in the present invention. The embodiments obtained by changing one or more of the above factors are verified by the same method as Examples 1-5. It is found that with the continuous increase of aging time, the tensile load loss rate of the embodiment samples is similar to that of Examples 1-5, and is maintained at a low level of about 10-15%; the nominal strain at break remains basically unchanged, and the loss rate of the dart impact damage mass is also maintained at about 10%.

[0079] Compared with the comparative film samples of the same type without the addition of powdered rubber, nucleating agent, UV crosslinking agent and other additives, the tensile load and dart impact strength of the above embodiments before aging are much higher than those of the comparative samples, which shows that the addition of powdered rubber, UV crosslinking agent and nucleating agent can improve the mechanical properties of the resin composition and meet the mechanical property requirements when cotton is packaged.

[0080] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

[0081] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0082] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0083] The endpoints and any values ​​of the scope disclosed in the present application document are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be considered as specifically disclosed in this article.

[0084] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

[0085] Moreover, any embodiment described in this document may be freely combined with one or more other embodiments described in this document, and the technical solutions or technical ideas formed thereby are deemed to be part of the original disclosure or original record of the present invention, and should not be regarded as new content that has not been disclosed or anticipated in this document, unless a person skilled in the art considers that the combination is obviously unreasonable.

Claims

1. A resin composition comprising LLDPE resin, a light stabilizer, an ultraviolet light crosslinking agent, a nucleating agent, rubber particles having a crosslinking structure, and optional additives; In parts by mass, relative to 100 parts of LLDPE resin, the resin composition contains 0.1-0.4 parts of light stabilizer, 0.2-0.6 parts of rubber particles with a cross-linked structure, 0.2-0.6 parts of nucleating agent, and 0.3-0.8 parts of ultraviolet cross-linking agent.

2. The resin composition according to claim 1, Features: The nucleating agent is selected from at least one of sorbitol derivative nucleating agents, organic carboxylic acid nucleating agents, organic carboxylate nucleating agents, and organic phosphate nucleating agents; preferably, The nucleating agent is selected from at least one of nucleating agent NA11, nucleating agent NA21, and nucleating agent 20E.

3. The resin composition according to claim 1, Features: The average particle size of the rubber particles is 0.02 to 2 microns, preferably 0.1 to 1 micron; and / or, The rubber particles are spherical; and / or, The rubber particles have a gel content of 60 wt % or more, preferably 80 wt % or more.

4. The resin composition according to claim 1, Features: The rubber particles are at least one of the following rubber particles having a cross-linked structure: Natural rubber, styrene-butadiene rubber, carboxylated styrene-butadiene rubber, nitrile rubber, carboxylated nitrile rubber, chloroprene rubber, polybutadiene, acrylic rubber, styrene-butadiene rubber, isoprene rubber, butyl rubber, ethylene-propylene rubber, polysulfide rubber, acrylate-butadiene rubber, polyurethane rubber or fluororubber, ethylene-vinyl acetate rubber.

5. The resin composition according to claim 1, Features: The rubber particles and the nucleating agent are derived from a resin nucleating agent containing both the rubber particles and the nucleating agent; Preferably, the mass ratio of the rubber particles to the nucleating agent in the resin nucleating agent is (3-7): (7-3) and / or, Preferably, the resin nucleating agent is selected from at least one of VP101B, VP101C, and VP801E.

6. The resin composition according to claim 1, Features: The ultraviolet crosslinking agent is selected from at least one of the crosslinking agents capable of undergoing isocyanate internal crosslinking and / or ketone hydrazine self-crosslinking reactions; preferably, The ultraviolet crosslinking agent is selected from at least one of trimethylolpropane triacrylate, benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diphenylacetophenone, α,α-dimethoxy-α-phenylacetophenone, α,α-diethoxyacetophenone, α-hydroxyalkylphenone, α-aminoalkylphenone, aromatic acylphosphine oxide, bisbenzoylphenylphosphine oxide, benzophenone, 2,4-dihydroxybenzophenone, thiopropoxythioxanthone and isopropylthioxanthone; more preferably, trimethylolpropane triacrylate.

7. The resin composition according to claim 1, Features: In parts by mass, the content of the light stabilizer is 0.2-0.4 parts relative to 100 parts of LLDPE resin; and / or, The light stabilizer is selected from at least one of the following light stabilizers: Salicylate light stabilizers, benzoate light stabilizers, benzophenone light stabilizers, benzotriazole light stabilizers, triazine light stabilizers, substituted acrylonitrile light stabilizers, oxamide light stabilizers, organic nickel complex light stabilizers, hindered amine light stabilizers; Preferably, the light stabilizer is selected from hindered amine light stabilizers, more preferably at least one selected from light stabilizer 944, light stabilizer 362 and light stabilizer 622.

8. The resin composition according to any one of claims 1 to 7, Features: The auxiliary agent includes an antioxidant; preferably, The antioxidant includes a primary antioxidant and a secondary antioxidant; more preferably, In parts by mass, relative to 100 parts of LLDPE resin, the amount of the primary antioxidant is 0.02-0.1 parts; the amount of the secondary antioxidant is 0.02-0.15 parts; and / or, More preferably, the primary antioxidant is a hindered phenol antioxidant, preferably at least one selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione; and / or, More preferably, the auxiliary antioxidant is selected from phosphites and / or thioester antioxidants, preferably selected from phosphites, including at least one of tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(octadecyl)pentaerythritol diphosphite, pentaerythritol bis(diphosphite (2,4-tert-butylphenyl) ester, bis(2,6-di-tert-butyl-4-tolyl)pentaerythritol phosphite, tetrakis(2,4-di-tert-butyloctaalkoxy-4,4'-biphenyl)phosphate, and 2,2-ethylenebis(4,6-di-tert-butylphenyl)fluorophosphite.

9. A method for preparing the resin composition according to any one of claims 1 to 8, comprising melt blending raw materials including the LLDPE resin, a light stabilizer, a nucleating agent, an ultraviolet light crosslinking agent, rubber particles having a crosslinking structure and optional additives to obtain the resin composition; preferably, Firstly, raw materials including LLDPE resin, light stabilizer, nucleating agent, ultraviolet crosslinking agent, rubber particles with crosslinking structure and optional auxiliary agents are premixed to obtain a premixed composition; then the premixed composition is melt-blended to obtain the resin composition.

10. A resin composition film, wherein the material of the resin composition film is the resin composition according to any one of claims 1 to 8 or the resin composition prepared by the preparation method according to claim 9; preferably, The average thickness of the resin composition film is 0.13-0.18 mm.

11. A method for preparing the resin composition film according to claim 10, comprising subjecting the resin composition according to any one of claims 1 to 8 or the resin composition prepared by the preparation method according to claim 9 to blow molding to obtain the resin composition film.

12. Use of the resin composition film according to claim 10 or the resin composition prepared by the preparation method according to claim 11 in the packaging field, preferably in the cotton packaging field.

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