Low-die-head-precipitation high-haze BOPP (Biaxially-oriented Polypropylene) extinction master batch and preparation method thereof

Abstract

The invention relates to the technical field of polypropylene films, in particular to a low-die-head-precipitation high-haze BOPP (biaxially-oriented polypropylene) extinction master batch and a preparation method thereof. The low-pressure high-density polyethylene composite material at least comprises the following preparation raw materials in parts by weight: 30 to 50 parts of co-polypropylene, 40 to 50 parts of low-pressure high-density polyethylene, 2 to 12 parts of polyolefin elastomer, 0.2 to 1.2 parts of inorganic delustering agent, 0.001 to 0.03 part of coupling agent, 0.01 to 0.3 part of cross-linking agent, 0.01 to 0.5 part of cross-linking aid, 0.001 to 0.1 part of processing aid and 0.5 to 1.5 parts of antioxidant. The BOPP matt film prepared from the provided BOPP matt master batch has excellent matt performance, processability and film surface condition, and better meets the actual application requirements.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene films, in particular to a low-die-head precipitated high-fog BOPP matting masterbatch and a preparation method thereof. Background Art

[0002] Biaxially oriented polypropylene film (BOPP) has high physical stability and mechanical strength, good air tightness, high transparency and glossiness, toughness and wear resistance, and is widely used in various fields, especially BOPP matte film is increasingly widely used in the packaging field. At present, BOPP matte film generally adopts the technical solution of blending polypropylene with polyethylene and adding matting agent or filler to achieve the matte effect of the film, such as a high haze HDPE matte masterbatch and its preparation method disclosed in a Chinese patent application (authorization announcement number CN115536929B), which mainly improves the haze and matte uniformity by using a branched polyethylene-b-random polypropylene block copolymer crystal region coupling agent, and ensures the processing performance by introducing a fluorine-containing polymer processing aid into the system, but the balance between matte performance, processing performance and film surface condition needs to be further improved. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch. By optimizing the coordination of the raw materials in the system, the BOPP matte film prepared from the provided BOPP matte masterbatch has excellent matte performance, processing performance and film surface condition, thus better meeting the actual application requirements.

[0004] On one hand, the present invention provides a low-die-precipitated high-haze BOPP matting masterbatch, wherein the raw materials for preparing the masterbatch at least comprise, by weight, 30-50 parts of copolymerized polypropylene, 40-50 parts of low-pressure high-density polyethylene, 2-12 parts of polyolefin elastomer, 0.2-1.2 parts of inorganic matting agent, 0.001-0.03 parts of coupling agent, 0.01-0.3 parts of cross-linking agent, 0.01-0.5 parts of cross-linking aid, 0.001-0.1 parts of processing aid and 0.5-1.5 parts of antioxidant.

[0005] As a preferred technical solution, the copolymerized polypropylene at least includes binary copolymerized polypropylene.

[0006] Preferably, the melt flow rate of the binary copolymer polypropylene (tested at 230° C., 2.16 kg, GB / T3682-2018) is 5-10 g / 10 min, preferably 8 g / 10 min, and the product model is Shanghai Petrochemical F800EDF.

[0007] As a preferred technical solution, the melt flow rate of the low-pressure high-density polyethylene (tested at 190°C, 21.6kg, GB / T 3682-2018) is 5-15g / 10min, preferably 7-12g / 10min, most preferably 9.8g / 10min, and the model is ExxonMobil HTA001HD5.

[0008] As a preferred technical solution, the polyolefin elastomer includes at least one of ethylene-propylene rubber (EPR), ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC).

[0009] Preferably, the polyolefin elastomer includes ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC).

[0010] Preferably, the mass ratio of the ethylene-propylene random copolymer, the vinyl polyolefin elastomer (POE) and the block vinyl polyolefin elastomer (OBC) is (2-6):(2-6):(2-6), preferably 6:2:2.

[0011] As an example, the mass ratios of the ethylene-propylene random copolymer, the vinyl polyolefin elastomer (POE), and the block vinyl polyolefin elastomer (OBC) are 2:2:6, 2:6:2, and 6:2:2.

[0012] Preferably, the model of the ethylene-propylene random copolymer is Yanshan Petrochemical B4808.

[0013] Preferably, the melt flow rate (190°C / 2.16kg, ASTM D1238) of the vinyl polyolefin elastomer is 20-40 g / 10 min, preferably 25-35 g / 10 min, most preferably 30 g / 10 min, and the model is Dow Chemical ENGAGE TM 8401.

[0014] Preferably, the melt flow rate (190°C / 2.16kg, ASTM D1238) of the block vinyl polyolefin elastomer is 10-20 g / 10 min, preferably 12-18 g / 10 min, most preferably 15 g / 10 min, and the model is Dow Chemical INFUSE TM 9817.

[0015] The present invention introduces a low-pressure high-density polyethylene with a melt flow rate (tested at 190°C, 21.6kg, GB / T 3682-2018) of 5-15g / 10min into the copolymerized polypropylene system, while providing the matting performance of the matting film product, having good film surface uniformity and fineness, while the introduction of linear low-density polyethylene or low-density polyethylene cannot simultaneously guarantee the above-mentioned matting performance, processing performance and film surface conditions. In particular, the mass ratio of the ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC) introduced into the control system is 6:2:2, so that the copolymerized polypropylene and the low-pressure high-density polyethylene have good compatibility, the crystallization is more refined, the haze can reach 85.3%, the die precipitation time is more than 96 hours, the film surface is uniform, fine and basically defect-free, thereby obtaining the best matting effect, meeting the practical application requirements of packaging box lamination, magazine cover lamination, etc.

[0016] As a preferred technical solution, the inorganic matting agent at least includes silicon dioxide, organic silicon microspheres and titanium dioxide.

[0017] Preferably, the mass ratio of the silicon dioxide, the silicone microspheres and the titanium dioxide is (1-5): (1-5): (1-5), preferably 5:3:1.

[0018] As an example, the mass ratios of silicon dioxide, silicone microspheres and titanium dioxide are 1:5:3, 3:1:5 and 5:3:1.

[0019] Preferably, the average particle size of the silicon dioxide is 2-10 μm, preferably 2.2-9.8 μm, most preferably 4.4-5.4 μm, and the model is SYLOBLOC 45 (Grace Company, USA).

[0020] Preferably, the average particle size of the organosilicon microspheres is 1-5 μm, preferably 1-3 μm, and most preferably 2 μm, and the model is KMP-590 (Shin-Etsu Chemical Co., Ltd.).

[0021] Preferably, the average particle size of the titanium dioxide is 0.1-1 μm, preferably 0.1-0.5 μm, most preferably 0.3 μm, and the model is R104 (Chemours Chemical (Shanghai) Co., Ltd.).

[0022] Furthermore, the present invention simultaneously introduces silica, silicone microspheres and titanium dioxide as inorganic matting agents in the optimized system, and coordinates the particle size control of silica, silicone microspheres and titanium dioxide to further improve the application performance of the matting masterbatch, so that a microscopic uneven structure can be formed on the surface of the BOPP film, and the matting effect of the product prepared subsequently is excellent, and the die precipitation time is further extended. In particular, the mass ratio of silica, silicone microspheres and titanium dioxide is controlled to be 5:3:1, and the matting efficiency is improved on the basis of ensuring that the haze and film surface of the matting film product prepared subsequently are uniform and delicate, and the problem of the matting masterbatch adsorbed on the metal surface of the die due to excessive precipitation of the die is reduced.

[0023] As a preferred technical solution, the coupling agent at least includes a titanate coupling agent and an aluminate coupling agent.

[0024] Preferably, the coupling agent is aluminum-titanium composite A4, which is sourced from Yizheng Tianyang Chemical Co., Ltd.

[0025] As a preferred technical solution, the cross-linking agent is peroxide.

[0026] Preferably, the peroxide comprises at least dicumyl peroxide (DCP).

[0027] As a preferred technical solution, the cross-linking auxiliary agent at least includes turpentine.

[0028] As a preferred technical solution, the processing aid is a fluorine-containing polymer processing aid, model PPA5911 (Shanghai Kaiyin Chemical Co., Ltd.).

[0029] As a preferred technical solution, the antioxidant is selected from at least one of hindered phenol antioxidants and phosphite antioxidants.

[0030] Preferably, the antioxidant is a combination of a hindered phenol antioxidant and a phosphite antioxidant, and the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is (1-3):1, preferably 2:1.

[0031] On the other hand, the present invention provides a method for preparing a low-die-precipitated high-haze BOPP matting masterbatch, which comprises at least the following steps: pretreating an inorganic matting agent with a coupling agent to obtain a powdery mixture, adding a processing aid and an antioxidant to obtain a composite powder package 1; mixing a crosslinking agent and a crosslinking aid to form a composite powder package 2; mixing copolymerized polypropylene, low-pressure high-density polyethylene, and a polyolefin elastomer to form a blended resin; melt-blending the blended resin, the composite powder package 1, and the composite powder package 2 through a twin-screw extruder, filtering the mixture, and extruding the mixture through a die, and then water-cooling, drawing, and pelletizing the mixture to obtain the masterbatch.

[0032] Preferably, the process parameters of the twin-screw extruder include: output 400-650 kg / h, screw speed 250-550 r / min, extruder temperature 180-260° C., and filter mesh size 300-600 mesh.

[0033] Preferably, the process parameters of the twin-screw extruder include: output 600kg / h, screw speed 500r / min, extruder zone 1 temperature 200°C, 2-15 zone temperature 220°C, filter mesh number 400 mesh, and screw arrangement of high shear and high dispersion distribution type.

[0034] Beneficial Effects

[0035] 1. The present invention provides a low-die-precipitated high-haze BOPP matte masterbatch. By optimizing the coordination of various raw materials in the system, the BOPP matte film prepared from the provided BOPP matte masterbatch has excellent matte performance, processing performance and film surface condition, which can better meet the actual application requirements.

[0036] 2. The present invention introduces a low-pressure high-density polyethylene with a melt flow rate (tested at 190°C, 21.6kg, GB / T 3682-2018) of 5-15g / 10min into the copolymerized polypropylene system, thereby providing the matte film product with matte performance while having good film surface uniformity and fineness.

[0037] 3. The present invention controls the mass ratio of ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC) introduced into the system to be 6:2:2, so that the copolymerized polypropylene and the low-pressure high-density polyethylene have good compatibility, the crystallization is more refined, the haze can reach 85.3%, the die head precipitation time is more than 96 hours, the film surface is uniform, delicate and basically defect-free, thereby obtaining the best matte effect and meeting the actual application needs of packaging box lamination, magazine cover lamination, etc.

[0038] 4. The present invention introduces silicon dioxide, silicone microspheres and titanium dioxide as inorganic matting agents in the optimized system at the same time, and controls the particle size of silicon dioxide, silicone microspheres and titanium dioxide to further improve the application performance of the matting masterbatch, so that a microscopic uneven structure can be formed on the surface of the BOPP film. The subsequently prepared product has excellent matting effect, and the die head precipitation time is further extended.

[0039] 5. The present invention controls the mass ratio of silicon dioxide, silicone microspheres and titanium dioxide to 5:3:1, thereby ensuring that the haze and film surface of the subsequently prepared matte film product are uniform and fine, thereby improving the matte efficiency and reducing the problem of matte masterbatch being adsorbed on the metal surface of the die due to excessive precipitation from the die. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a reference chart for judging the level of film surface fineness in Table 1. From top to bottom in the figure, it corresponds to levels 1-5, and the left and right are parallel samples.

[0041] Figure 2 This is a reference chart for judging the film surface uniformity level in Table 1. From top to bottom in the figure, it corresponds to levels 1-3 respectively, and the left and right are parallel samples. DETAILED DESCRIPTION

[0042] Example 1

[0043] Embodiment 1 of the present invention provides a low-die-precipitated high-haze BOPP matting masterbatch, wherein the raw materials for its preparation include, by weight: 42.92 parts of copolymerized polypropylene, 45 parts of low-pressure high-density polyethylene, 10 parts of polyolefin elastomer, 0.9 parts of inorganic matting agent, 0.01 parts of coupling agent, 0.1 parts of cross-linking agent, 0.3 parts of cross-linking aid, 0.02 parts of processing aid, and 0.75 parts of antioxidant.

[0044] The copolymer polypropylene is a binary copolymer polypropylene, the melt flow rate of the binary copolymer polypropylene (tested at 230° C. and 2.16 kg, GB / T 3682-2018) is 8 g / 10 min, and the product model is Shanghai Petrochemical F800EDF.

[0045] The melt flow rate of the low-pressure high-density polyethylene (tested at 190°C and 21.6kg, GB / T3682-2018) is 9.8g / 10min, and the model is ExxonMobil HTA001HD5.

[0046] The polyolefin elastomer includes ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC).

[0047] The mass ratio of the ethylene-propylene random copolymer, the vinyl polyolefin elastomer (POE), and the block vinyl polyolefin elastomer (OBC) is 6:2:2.

[0048] The model of the ethylene-propylene random copolymer is Yanshan Petrochemical B4808; the melt flow rate of the vinyl polyolefin elastomer (190°C / 2.16kg, ASTMD1238) is 30g / 10min, and the model is Dow Chemical ENGAGE TM 8401; the melt flow rate of the block vinyl polyolefin elastomer (190°C / 2.16kg, ASTM D1238) is 15g / 10min, and the model is Dow Chemical INFUSE TM 9817.

[0049] The inorganic matting agent is a combination of silicon dioxide, organic silicon microspheres and titanium dioxide, and the mass ratio of the silicon dioxide, organic silicon microspheres and titanium dioxide is 5:3:1.

[0050] The average particle size of the silicon dioxide is 4.4-5.4 μm, and the model is SYLOBLOC 45 (Grace Company, USA); the average particle size of the silicone microspheres is 2 μm, and the model is KMP-590 (Shin-Etsu Chemical Co., Ltd.); the average particle size of the titanium dioxide is 0.3 μm, and the model is R104 (Chemours Chemical (Shanghai) Co., Ltd.).

[0051] The coupling agent is aluminum-titanium composite type A4, which comes from Yizheng Tianyang Chemical Co., Ltd.

[0052] The cross-linking agent is a peroxide, and the peroxide is dicumyl peroxide (DCP).

[0053] The cross-linking auxiliary agent is turpentine (Jiangxi Xuesong Natural Medicinal Oil Co., Ltd.).

[0054] The processing aid is a fluorine-containing polymer processing aid, model PPA5911 (Shanghai Kaiyin Chemical Co., Ltd.).

[0055] The antioxidant is a combination of a hindered phenol antioxidant and a phosphite antioxidant, and the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 2:1.

[0056] The hindered phenol antioxidant is antioxidant 1010 (BASF), and the phosphite antioxidant is antioxidant 168 (BASF).

[0057] On the other hand, embodiment 1 of the present invention provides a method for preparing a low-die-precipitated high-haze BOPP matting masterbatch, comprising the following steps: pre-treating an inorganic matting agent with a coupling agent to obtain a powdered mixture, adding a processing aid antioxidant to obtain a composite powder package 1; mixing a cross-linking agent and a cross-linking aid to form a composite powder package 2; mixing copolymerized polypropylene, low-pressure high-density polyethylene, and a polyolefin elastomer to form a blended resin; melt-blending the blended resin, composite powder package 1, and composite powder package 2 through a twin-screw extruder, extruding through a die after filtering, and then water-cooling and drawing pelletizing to obtain the result. The process parameters of the twin-screw extruder include: an output of 600kg / h, a screw speed of 500r / min, an extruder zone 1 temperature of 200°C, a zone 2-15 temperature of 220°C, a filter mesh of 400 mesh, and a screw arrangement of a high-shear high-dispersion distribution type.

[0058] Example 2

[0059] Example 2 of the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch and a preparation method thereof. Its specific implementation method is the same as that of Example 1, except that the mass ratio of the ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC) is 2:2:6.

[0060] Example 3

[0061] Example 3 of the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch and a preparation method thereof. Its specific implementation method is the same as that of Example 1, except that the mass ratio of the ethylene-propylene random copolymer, vinyl polyolefin elastomer (POE), and block vinyl polyolefin elastomer (OBC) is 2:6:2.

[0062] Example 4

[0063] Example 4 of the present invention provides a low-die-precipitated high-haze BOPP matting masterbatch and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the mass ratio of the silica, silicone microspheres and titanium dioxide is 3:1:5.

[0064] Example 5

[0065] Example 5 of the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch and a preparation method thereof, and its specific implementation method is the same as that of Example 1, except that the mass ratio of the silica, silicone microspheres and titanium dioxide is 1:5:3.

[0066] Comparative Example 1

[0067] Comparative Example 1 of the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch and a preparation method thereof, and its specific implementation manner is the same as that of Example 1, except that the low-pressure high-density polyethylene is replaced by an equal amount of low-density polyethylene, and the model is CNOOC Shell 2420K.

[0068] Comparative Example 2

[0069] Comparative Example 2 of the present invention provides a low-die-precipitated high-haze BOPP matte masterbatch and a preparation method thereof, and its specific implementation method is the same as that of Example 1, except that the low-pressure high-density polyethylene is replaced by an equal amount of linear low-density polyethylene, model CNOOC Shell 7042.

[0070] Comparative Example 3

[0071] Comparative Example 3 of the present invention provides a low-die-precipitated high-haze BOPP matting masterbatch and a preparation method thereof, and its specific implementation method is the same as that of Example 1, except that the inorganic matting agent is replaced by an equal amount of silicon dioxide with a particle size of 50-100 nm, and the model is MSNs (Nanjing Donna Biotechnology Co., Ltd.).

[0072] Comparative Example 4

[0073] Comparative Example 4 of the present invention provides a low-die-precipitated high-haze BOPP matting masterbatch and a preparation method thereof, and its specific implementation method is the same as that of Example 1, except that the inorganic matting agent is replaced by an equal amount of silicon dioxide with a particle size of 7 μm and a model of C807 (Grace Company, USA).

[0074] Performance Testing

[0075] 1. The matte masterbatch provided in the embodiment and the comparative example was used to prepare a BOPP matte film according to the following method. The BOPP matte film was tested for various properties listed in Table 1. The test reference standards and test results are shown in Table 1.

[0076] Table 1

[0077]

[0078] In Table 1, the criteria for judging the degree of film surface fineness refer to Figure 1 The film surface fineness decreases from level 1 to level 5, with level 1 being the finest and level 5 being the roughest. For the criteria for determining the uniformity of the film surface, see Figure 2 The uniformity of the membrane surface decreases from level 1 to level 3, with level 1 being the most uniform and level 3 being the least uniform. For the criteria for determining the level of die head precipitation time, see Table 2.

[0079] Table 2

[0080] Level / G Criteria 1 G≥96h 2 48≤G<96h 3 12≤G<48h 4 G<12h

Claims

1. A low die head precipitation high haze BOPP matte masterbatch, characterized in that: The raw materials for its preparation include at least 30-50 parts of copolymerized polypropylene, 40-50 parts of low-pressure high-density polyethylene, 2-12 parts of polyolefin elastomer, 0.2-1.2 parts of inorganic matting agent, 0.001-0.03 parts of coupling agent, 0.01-0.3 parts of cross-linking agent, 0.01-0.5 parts of cross-linking aid, 0.001-0.1 parts of processing aid and 0.5-1.5 parts of antioxidant.

2. The low die head precipitation high haze BOPP matting masterbatch according to claim 1, characterized in that: The copolymerized polypropylene at least comprises binary copolymerized polypropylene, and the melt flow rate of the binary copolymerized polypropylene is 5-10 g / 10 min.

3. The low die head precipitation high haze BOPP matting masterbatch according to claim 1, characterized in that: The melt flow rate of the low-pressure high-density polyethylene is 5-15 g / 10 min.

4. The low die head precipitation high haze BOPP matting masterbatch according to claim 1, characterized in that: The polyolefin elastomer includes at least one of ethylene-propylene rubber, ethylene-propylene random copolymer, vinyl polyolefin elastomer, and block vinyl polyolefin elastomer.

5. The low die head precipitation high haze BOPP matting masterbatch according to claim 4, characterized in that: The melt flow rate of the vinyl polyolefin elastomer is 20-40 g / 10 min.

6. The low die head precipitation high haze BOPP matting masterbatch according to claim 4, characterized in that: The melt flow rate of the block vinyl polyolefin elastomer is 10-30 g / 10 min.

7. The low die head precipitation high haze BOPP matte masterbatch according to claim 1, characterized in that: The inorganic matting agent at least includes silicon dioxide, organic silicon microspheres and titanium dioxide.

8. The low die head precipitation high haze BOPP matte masterbatch according to claim 7, characterized in that: The mass ratio of the silicon dioxide, the organic silicon microspheres and the titanium dioxide is (1-5): (1-5): (1-5).

9. The low die head precipitation high haze BOPP matting masterbatch according to claim 8, characterized in that: The coupling agent at least includes a titanate coupling agent and an aluminate coupling agent.

10. A method for preparing a low die head precipitated high haze BOPP matting masterbatch according to any one of claims 1 to 9, characterized in that: At least the following steps are included: The inorganic matting agent is pretreated with a coupling agent to obtain a powder mixture, and a processing aid antioxidant is added to obtain a composite powder package 1; a crosslinking agent and a crosslinking aid are mixed to obtain a composite powder package 2; copolymerized polypropylene, low-pressure high-density polyethylene, and a polyolefin elastomer are mixed to obtain a blended resin; the blended resin, the composite powder package 1, and the composite powder package 2 are melt-blended by a twin-screw extruder, filtered through a screen, extruded through a die head, and then water-cooled, stretched, and pelletized to obtain the product.

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