A kind of anti-reflection and stiffening masterbatch for cast polypropylene film and its preparation process

Abstract

The present application relates to the technical field of polypropylene film, in particular to a kind of flow casting polypropylene film with transmittance and stiffness increasing master batch and its preparation process, at least including: thermoplastic resin 85-95 parts, third generation sorbitol 1-10 parts, dispersing agent 0.5-1 part, antioxidant 0.1-0.5 part by weight parts, by optimizing product formula system, the master batch with obvious transmittance and stiffness increasing effect is prepared at lower raw material cost, and the preparation method is simple, easy to realize large-scale industrial production and popularization and application.

Description

Technical Field

[0001] This invention relates to the field of polypropylene film technology, specifically to an antireflective and stiffening masterbatch for cast polypropylene film and its preparation process. Background Technology

[0002] Polypropylene (PP) has low density, good heat and chemical resistance, is non-toxic and odorless, has a good surface gloss, and excellent overall performance, making it widely used in packaging for food, candy, cigarettes, tea, juice, milk, textiles, etc. Currently, with industrial development and improved living standards, the performance requirements for packaging films are also increasing, especially for stiffness and transparency. For example, a stiffening masterbatch and its preparation method, polyolefin film, and BOPP film disclosed in Chinese patent application (authorization announcement number CN113861565B) mainly introduce a cage-type polysilsesquioxane-g-graphene@SiO2 three-dimensional network structure into the PP matrix as a stiffening agent, and add a compatibilizer. After melt blending, a PP-compatibilizer-cage-type polysilsesquioxane-g-graphene@SiO2 composite system is formed as a stiffening masterbatch for polyolefin films. This method has high raw material costs, complex preparation processes, and requires the addition of approximately 10wt% to maintain the stiffness of the polyolefin film, resulting in high operating costs and making it difficult to achieve large-scale industrial production. Chinese patent application (publication number CN 111378224 A) discloses an anti-reflection and stiffening masterbatch for cast polypropylene film and its preparation process. It uses nano-barium sulfate treated with silane coupling agent and organic anti-reflection agent to improve transparency, but the anti-reflection effect needs to be further improved. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides an anti-reflection and stiffening masterbatch for cast polypropylene films. By optimizing the product formulation system, a masterbatch with significant anti-reflection and stiffening effects can be prepared at a lower raw material cost. Furthermore, the preparation method is simple and easy to implement for large-scale industrial production and widespread application.

[0004] The present invention provides a masterbatch for enhancing transparency and stiffness in cast polypropylene film, wherein the raw materials for preparation include at least the following by weight: 85-95 parts of thermoplastic resin, 1-10 parts of third-generation sorbitol, 0.5-1 parts of dispersant, and 0.1-0.5 parts of antioxidant.

[0005] As a preferred technical solution, the melt flow rate of the thermoplastic resin (tested at 230℃ and 2.16kg, GB / T 3682-2018) is 7-20g / 10min, preferably 10-20g / 10min, and most preferably 17±3g / 10min.

[0006] As a preferred technical solution, the isotactic index (SH / T1774-2012) of the thermoplastic resin is ≥95.0wt%.

[0007] Preferably, the thermoplastic resin is an injection molding polypropylene resin with a melt flow rate (tested at 230℃ and 2.16kg, GB / T 3682-2018) of 17.6g / 10min, an isotactic index (SH / T1774-2012) of 97.9wt%, and a product model of Gulei PPH-M17.

[0008] As a preferred technical solution, the melting point of the third-generation sorbitol is ≥200℃; more preferably, the melting point of the third-generation sorbitol is ≥260℃.

[0009] As a preferred technical solution, the third-generation sorbitol is selected from at least one of 1,3:2,4-(4′-propylbenzylene)-1-propylsorbitol, 1,3:2,4-dibenzylene sorbitol, 1,3:2,4-di(p-methylbenzylene)sorbitol, and 1,3:2,4-di(3,4-dimethylbenzylene)-D-sorbitol, preferably 1,3:2,4-di(3,4-dimethylbenzylene)-D-sorbitol (CAS No.: 135861-56-2).

[0010] As an example, the third-generation sorbitol is selected from BLK-7981, BLK-7988, BLK-7983, At least one of 3988, preferably BLK-7988 or 3988.

[0011] As a preferred technical solution, the dispersant is selected from at least one of fatty acid dispersants and wax dispersants.

[0012] Preferably, the fatty acid dispersant includes at least ethylene bis-stearamide.

[0013] Preferably, the wax dispersant includes at least polyethylene wax.

[0014] As a preferred technical solution, the antioxidant is selected from at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0015] Preferably, the antioxidant is a combination of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:(1-3), preferably 1:2.

[0016] The antireflective masterbatch provided by this invention, using injection-molded polypropylene resin with a melt flow rate of 7-20 g / 10 min and an isotactic index ≥95.0 wt%, facilitates processing and crystallization. Furthermore, the use of third-generation sorbitol with a melting point ≥260℃ as a nucleating agent ensures good compatibility with polypropylene resin. In the presence of a dispersant, it significantly improves transparency, gloss, and physical and mechanical properties, guaranteeing optimal performance in subsequent applications. Especially when the dispersant includes ethylene bis-stearamide or polyethylene wax, it enhances the dispersibility of the system and the mechanical properties of the product, leading to the subsequent preparation of high-stiffness, high-strength, and high-toughness plastic composite materials.

[0017] Another aspect of the present invention provides a method for preparing a masterbatch for casting polypropylene film that enhances transparency and stiffness, comprising at least the following steps: premixing third-generation sorbitol, dispersant, and antioxidant to obtain a mixed powder; adding thermoplastic resin and the mixed powder through two main feed ports of a twin-screw extruder, heating and melting the mixture, extruding and granulating, cooling and cutting into pellets, and drying to obtain the final product.

[0018] As a preferred technical solution, the process parameters of the twin-screw extruder include: output of 500-600 kg / h; main extruder speed of 300-400 r / min; extruder zone 1-6 temperature of 190-200℃, zone 7-10 temperature of 175-185℃, zone 11-15 temperature of 150-170℃, die head temperature of 230-260℃, transition body temperature of 230-260℃; filter mesh size of 200-300 mesh, and number of filter layers of 3-6.

[0019] Preferably, the process parameters of the twin-screw extruder include: output of 600 kg / h; main extruder speed of 350 r / min; extruder zone 1-6 temperature of 190℃, zone 7-10 temperature of 180℃, zone 11-15 temperature of 160℃, die head temperature of 250℃, transition body temperature of 250℃; filter mesh of 250 mesh, and filter layers of 5 layers.

[0020] As a preferred technical solution, the pelletizing speed is 2000-3000 rpm, preferably 2800 rpm.

[0021] This invention optimizes the production process of the anti-reflection masterbatch, achieving low-temperature production, resulting in a whiter and more transparent appearance, smaller and more uniform size of the provided masterbatch, and better dispersion effect when used on films, effectively improving the appearance of films and reducing color change problems.

[0022] The third aspect of this invention provides an application of an anti-reflection and stiffening masterbatch for cast polypropylene film, which is used in the preparation of cast polypropylene film products, wherein the amount of anti-reflection and stiffening masterbatch added to the cast polypropylene film products is ≤5wt%.

[0023] The antireflective masterbatch provided by this invention, when added to a cast polypropylene film system at ≤5wt%, significantly improves the optical and mechanical properties of the cast polypropylene film, greatly reduces the cost of use, and has extremely high market promotion value.

[0024] Beneficial effects

[0025] 1. This invention provides an anti-reflection and stiffening masterbatch for cast polypropylene films. By optimizing the product formulation system, a masterbatch with significant anti-reflection and stiffening effects can be prepared at a lower raw material cost. Moreover, the preparation method is simple and easy to realize large-scale industrial production and promotion.

[0026] 2. The antireflective masterbatch provided by the present invention, by using injection-molded polypropylene resin with a melt flow rate of 7-20 g / 10 min and an isotactic index ≥ 95.0 wt%, is beneficial for processing and crystallization.

[0027] 3. This invention uses third-generation sorbitol with a melting point ≥260℃ as a nucleating agent, which has good compatibility with polypropylene resin. In the presence of a dispersant, it significantly improves transparency, gloss and physical and mechanical properties, ensuring the effect of subsequent applications. In particular, when the dispersant includes ethylene bis-stearamide or polyethylene wax, it improves the dispersibility of the system and the mechanical properties of the product, and can be used to prepare plastic composite materials with high stiffness, high strength and high toughness.

[0028] 4. This invention optimizes the production process of the enhanced transparency masterbatch, achieving low-temperature production, resulting in a whiter and more transparent appearance, smaller and more uniform size of the provided masterbatch, and better dispersion effect when used on films, effectively improving the appearance of films and reducing color change problems.

[0029] 5. The antireflective masterbatch provided by this invention, when added to the cast polypropylene film system at ≤5wt%, significantly improves the optical and mechanical properties of the cast polypropylene film, greatly reduces the cost of use, and has extremely high market promotion value. Attached Figure Description

[0030] Figure 1 The image shows a comparison of the stiffness of cast polypropylene film products provided in Application Example 1 and Application Comparative Example. The upper part of the image shows the cast polypropylene film product provided in Application Comparative Example, and the lower part shows the cast polypropylene film product provided in Application Example 1. Detailed Implementation

[0031] Examples 1-2, Comparative Examples 1-2

[0032] Examples 1-2 and Comparative Examples 1-2 of the present invention provide an antireflective and stiffening masterbatch for cast polypropylene film, the formulation of which is shown in Table 1 by weight.

[0033] Table 1

[0034]

[0035] In Table 1: the model number of the third-generation sorbitol is... 3988; the polyethylene wax model is SX-110B, sourced from Guangzhou Bohan Chemical Co., Ltd.; the ethylene bis-stearamide model is Kao EBS; the composite antioxidant is composed of BASF 1010 and BASF 168 in a mass ratio of 1:2; the nano silica model is A200, sourced from Evonik Chemical.

[0036] Examples 1-2 and Comparative Examples 1-2 of the present invention provide a method for preparing a masterbatch for enhancing transparency and stiffness in cast polypropylene film, comprising the following steps: premixing third-generation sorbitol, dispersant, and antioxidant to obtain a mixed powder; weighing thermoplastic resin and the mixed powder using a loss-in-weight scale (accuracy 0.1 kg), adding them through two main feed ports of a twin-screw extruder, heating and melting the mixture, extruding and granulating, cooling and pelletizing, and drying to obtain the final product; the process parameters of the twin-screw extruder include: output of 600 kg / h; main extruder speed of 350 r / min; extruder zone 1-6 temperature of 190℃, zone 7-10 temperature of 180℃, zone 11-15 temperature of 160℃, die head temperature of 250℃, transition body temperature of 250℃; filter mesh of 250 mesh, number of filter layers of 5; and pelletizing speed of 2800 rpm.

[0037] Application Examples 1-2, Comparative Examples 1-2

[0038] Application Examples 1-2 and Comparative Examples 1-2 of the present invention provide a cast polypropylene film product, comprising a core layer, a heat-sealing layer, and a corona layer, wherein the core layer is in the middle, and the heat-sealing layer and the corona layer are respectively on both sides of the core layer. The formulation is shown in Table 2.

[0039] Table 2

[0040]

[0041] The method for preparing the cast polypropylene film product is as follows: the cast polypropylene film is mixed with polypropylene using an anti-reflection and stiffening masterbatch to obtain a core layer material, and the core layer material, heat-sealing layer material, and corona layer material are used to prepare a three-layer structure cast polypropylene film product with a thickness of 35±5μm through a casting film forming process.

[0042] Performance testing

[0043] 1. Optical and mechanical properties of the cast polypropylene film products provided in the application examples and comparative examples were tested. The optical properties were tested according to GB / T 2410, and the mechanical properties were tested according to GB / T 1040. The test results are shown in Table 3.

[0044] Table 3

[0045]

[0046]

[0047] In Table 3: T: transmittance, H: haze, C: clarity, G: gloss.

[0048] 2. The stiffness of the cast polypropylene film products provided in Application Example 1 and the control example was tested. The results are shown in [reference needed]. Figure 1 As can be seen from the comparison, adding the antireflective masterbatch provided in Example 1 to the polypropylene film can effectively improve the stiffness of the film.

Claims

1. A masterbatch for enhancing the clarity and stiffness of cast polypropylene film, characterized in that, The raw materials for its preparation, by weight, are: 85-95 parts of thermoplastic resin, 1-10 parts of third-generation sorbitol, 0.5-1 parts of dispersant, and 0.1-0.5 parts of antioxidant; the thermoplastic resin is injection-molded polypropylene resin with a melt flow rate of 17.6 g / 10 min, an isotactic index of 97.9 wt%, and the product model is Gulei PPH-M17; the third-generation sorbitol is 1,3:2,4-di(3,4-dimethylbenzyl)-D-sorbitol, model BLK-7988 or Millad® 3988; the dispersant is ethylene bis-stearamide or polyethylene wax; the antioxidant is a combination of antioxidant 1010 and antioxidant 168, with a mass ratio of antioxidant 1010 to antioxidant 168 of 1:

2.

2. A method for preparing the antireflective and stiffening masterbatch for cast polypropylene film according to claim 1, characterized in that, At least the following steps are included: The third-generation sorbitol, dispersant, and antioxidant are premixed to obtain a mixed powder; the thermoplastic resin and the mixed powder are added through the two main feed ports of a twin-screw extruder, heated and melted, then extruded, granulated, cooled, granulated, and dried to obtain the final product. The process parameters of the twin-screw extruder include: the temperature of zones 1-6 of the extruder is 190~200℃, the temperature of zones 7-10 is 175~185℃, the temperature of zones 11-15 is 150~170℃, the die head temperature is 230~260℃, and the transition body temperature is 230~260℃.

3. The application of the antireflective and stiffening masterbatch for cast polypropylene film according to claim 1, characterized in that, This material is used in the preparation of cast polypropylene film products, wherein the amount of antireflective and stiffening masterbatch added to the cast polypropylene film product is ≤5wt.

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