Semi-dull master batch and film packaging material

Abstract

The invention provides a semi-matt master batch and a film packaging material, and relates to the field of semi-matt films, the semi-matt master batch comprises the following components by weight: 45-65 parts of impact-resistant copolymerized PP, 35-55 parts of HDPE, 0.1-0.8 part of an antioxidant, 2-8 parts of silicone rubber, and 0.1-2 parts of an auxiliary agent; according to the invention, the dosage ratio of PP resin to HDPE is creatively and greatly adjusted to exceed the range of the conventional dosage ratio in the process of preparing the semi-dull master batch, specifically, the dosage of PP is reduced to 45-65 parts, the dosage of HDPE is increased to 35-55 parts, and meanwhile, high-fluidity impact-resistant PP is used, so that the cost is reduced, higher rigidity is brought to the film, and the service life of the film is prolonged. The defect of uneven stretching thickness is overcome, stretching lines are thoroughly eliminated, and the thin film with uniform thickness and height is obtained.

Description

Technical Field

[0001] This invention relates to the field of semi-matte masterbatch technology, specifically to a semi-matte masterbatch and film packaging material. Background Technology

[0002] Biaxially oriented polypropylene (BOPP) film is widely used in production and daily life, and semi-matte film is a type of BOPP film. BOPP semi-matte film, also known as matte transfer base film, has advantages such as high matteness (haze value generally below 60, while full-matte film haze value is generally above 70) and low gloss, exhibiting a diffuse reflection matte effect, good ink absorption, and good transfer effect. Besides its use in packaging, it is a new type of film suitable for transfer printing on textiles and PU leather. Unlike traditional PET film, it does not require a release liner for direct printing transfer. The semi-matte masterbatch, as the functional raw material of semi-matte film, directly affects the film's appearance, feel, and mechanical properties.

[0003] One existing method for preparing BOPP semi-matte masterbatch involves adding a certain amount of polypropylene and other small amounts of additives to an existing full-matte masterbatch formulation, premixing it, and then using it as a semi-matte masterbatch. However, the semi-matte transfer film prepared by this method suffers from unstable distribution and poor uniformity of the semi-matte effect due to uneven dispersion of the premixed full-matte material in the matte layer, resulting in a noticeable cloud-like appearance and failing to achieve the desired decorative effect after transfer. Another method involves using random copolymer polypropylene (melt index typically 6-10 g / 10min) as the continuous phase in existing semi-matte masterbatches, blending it with high-density polyethylene (HDPE) to form a matte structure. The conventional amount of random copolymer polypropylene in this formulation is generally 67-89 parts by weight. For example, patent application CN107603008A discloses a semi-matte masterbatch that mainly contains 66.7-86.9 parts of PP resin (melt index 3-15 g / 10min) and 8-18 parts of HDPE (melt index 6-12). (g / 10min) and compatibilizers, etc.

[0004] In order to further reduce costs and improve the rigidity of the film, the applicant attempted to reduce the amount of the more expensive PP component based on the above-mentioned existing technology. However, this adjustment of the amount resulted in a significant reduction in the mechanical properties of the film. In addition, adding a higher performance resin (melt index 25-60 g / 10min) caused unexpected technical problems in the subsequent biaxial stretching film formation process: the film was prone to extremely uneven thickness distribution (extremely poor thickness dispersion), which became a technical bottleneck for the industrialization of this low-cost, high-performance formulation route.

[0005] Therefore, this application aims to solve the problem of uneven film thickness distribution mentioned above, in order to obtain a semi-dull film with low cost and strong mechanical properties. In addition, existing technologies for controlling the haze of semi-dull films (usually required to be between 30-60) mostly rely on adjusting the PP ratio, which is a relatively simple control method with insufficient precision. Summary of the Invention

[0006] The present invention addresses the aforementioned problems existing in the prior art by providing a semi-matte masterbatch and a film packaging material.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: On one hand, the present invention provides a semi-matte masterbatch, characterized in that it comprises the following components and their weight proportions: Impact copolymer PP 45-65 parts HDPE 35-55 parts Antioxidant 0.1-0.8 parts 2-8 parts silicone rubber Additives: 0.1-2 parts.

[0008] Furthermore, the impact-resistant copolymer PP is a highly crystalline impact-resistant polypropylene with a melt index of 25-60 g / 10min, an ethylene mass fraction of 6-15%, and an ethylene-propylene random copolymer content of 5-25%. Preferably, at least one of BH3900, PP7555KNE2, and EP533N type polypropylene is used.

[0009] This invention selects highly crystalline, impact-resistant polypropylene as the matrix resin. Because the two ethylene monomers and three other monomers in the block copolymer polypropylene are linked together, the ethylene monomers exist only in the block phase and do not alter the regularity of the polypropylene. Its high fluidity allows for lower processing temperatures and extrusion pressures during product manufacturing, thereby reducing energy consumption and shortening the product molding cycle. The higher flexural modulus and wider molecular weight distribution of the polypropylene allow HDPE and impact-resistant PP to form a uniform blended network structure under high-speed operation in the granulation extruder.

[0010] Furthermore, the melt index of the HDPE is 0.05-0.8 g / 10min.

[0011] Furthermore, the antioxidant is at least one of BASF1010, BASF168, BASF1141, and BASF1098.

[0012] Furthermore, the additive is at least one of hydrogenated petroleum resin and erucamide.

[0013] Furthermore, the silicone rubber is methyl vinyl silicone rubber, with a vinyl content of 0.1-0.3 mol% and a molecular weight of 500,000-700,000.

[0014] Furthermore, the preparation method of the semi-matte masterbatch is as follows: after mixing the raw materials, the mixture is melt-extruded through an extruder, and then stretched, cooled, dried, and pelletized to obtain the semi-matte masterbatch.

[0015] On one hand, the present invention provides a film packaging material, characterized in that it comprises an anti-adhesion layer, an antistatic layer and a semi-matte layer arranged in sequence, wherein the semi-matte layer is formed by melt co-extrusion of the semi-matte masterbatch as described above.

[0016] The beneficial effects of this invention are: 1. This invention innovatively adjusts the ratio of PP resin and HDPE to a significantly higher range than conventional ratios during the preparation of semi-matte masterbatch. Specifically, the PP content is reduced to 45-65 parts, and the HDPE content is increased to 35-55 parts. Simultaneously, high-flowability, impact-resistant PP is used, reducing costs while providing higher rigidity to the film. Based on this ratio, this invention further solves the "uneven stretching thickness" defect present in the above formulation by limiting the material properties and using silicone rubber, completely eliminating stretch marks and obtaining a film with highly uniform thickness.

[0017] 2. In the formulation system of this invention, this invention creatively discovers that hydrogenated petroleum resin can play the role of a haze regulator in this specific system. That is, under this formulation system, the haze value of the semi-matte film can be precisely controlled within a wide range of 30-60 by changing the amount of hydrogenated petroleum resin added. The control method is simple and efficient. Detailed Implementation

[0018] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] All parts mentioned in the following examples and comparative examples refer to parts by weight.

[0020] Example 1 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation, Korea BH3900 (60 g / 10 min): 48.5 parts; High-density polyethylene - LyondellBasell Group Lupolen 4261A (0.5 g / 10min, 0.94 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0021] Example 2 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - ExxonMobil PP7555KNE2 (50 g / 10 min): 48.5 parts; High-density polyethylene - Dow HDPE DGDA-2484 NT (0.07 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0022] Example 3 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts; Example 4 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Additives (erucamide and hydrogenated petroleum resin in a ratio of 1:10): 3.3 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0023] Example 5 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Additives (erucamide and hydrogenated petroleum resin in a 1:5 ratio): 1.8 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0024] Example 6 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Additives (erucamide and hydrogenated petroleum resin in a ratio of 1:15): 4.8 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0025] Example 7 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010, 168 and 1141 in a mass ratio of 1:3:1): 0.2 parts.

[0026] Example 8 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 45 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 52.5 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0027] Example 9 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 55 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 42.5 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0028] Example 10 The semi-matte masterbatch formulation of this embodiment is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 65 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 32.5 copies; Additive - Erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0029] The formulations described in the above examples are added step by step. PP, PE, and silicone rubber are fed in through feed port 1, while additives and antioxidants are fed in through the side feed port. The mixture is melt-extruded into strips using a twin-screw extruder. The strips are then granulated and dried to produce semi-matte finish material. The twin-screw extruder used has a production temperature of 170℃ in zone 1, 220℃ in zones 2-11, a die temperature of 205℃, a rotation speed controlled at 220-280 r / min, a die head pressure controlled at 2-5 MPa, and an underwater temperature controlled at approximately 15℃.

[0030] Comparative Example 1 The semi-matte masterbatch formulation in this comparative example is basically the same as that in Example 1, except that it does not contain silicone rubber. The specific formulation is as follows: Impact-resistant polypropylene copolymer - SK Corporation, Korea BH3900 (60 g / 10 min): 48.5 parts; High-density polyethylene - LyondellBasell Group Lupolen 4261A (0.5 g / 10min, 0.94 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0031] Comparative Example 2 The semi-matte masterbatch formulation in this comparative example is basically the same as that in Example 2, except that it does not contain silicone rubber. The specific formulation is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio 1:1); High-density polyethylene - Dow HDPE DGDA-2484 NT (0.07 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0032] Comparative Example 3 The semi-matte masterbatch formulation of this comparative example is basically the same as that of Example 3, except that it does not contain silicone rubber. The specific formulation is as follows: impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 48.5 parts (mixing ratio is 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 49 copies; Additive - Erucamide: 0.3 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0033] Comparative Example 4 The semi-matte masterbatch formulation for this comparative example is as follows: Random copolymer polypropylene (8 g / 10 min): 70 parts; High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 30 copies; Additive - Erucamide: 0.3 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0034] Comparative Example 5 The masterbatch formulation of this comparative example is basically the same as that of Example 3, except that the impact-resistant polypropylene copolymer is replaced with an equal mass of random copolymer polypropylene (8 g / 10 min).

[0035] Comparative Example 6 The masterbatch formulation of this comparative example is basically the same as that of Example 3, except that the ratio of impact-resistant polypropylene copolymer to HDPE is changed. The specific formulation is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 86.8 parts (mixing ratio 1:1); High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 8 parts of auxiliary agent - erucamide: 0.3 parts; Silicone rubber (methyl vinyl, molecular weight 600,000): 2 parts; Antioxidant (a compound of 1010 and 168, in a mass ratio of 1:3): 0.2 parts.

[0036] Comparative Example 7 The masterbatch formulation for this comparative example is adapted from the formulation of Example 3 in patent document CN107603008A. Based on this, the binary copolymer polypropylene is replaced with the impact-resistant polypropylene copolymer of Example 3 of this invention. The high-density polyethylene is replaced with HDPE of Example 1. The specific formulation is as follows: Impact-resistant polypropylene copolymer - SK Corporation of Korea BH3900 (60 g / 10min) and Lanzhou Petrochemical of China EP533N (35 g / 10min): 86.8 parts; High-density polyethylene - ExxonMobil HDPE HD5 (0.68 g / 10min, 0.95 g / cm³) 3 ): 8 copies; Compatibilizer – Dow Chemical 2045G (1.0 g / 10 min, 0.920 g / cm³) 3 : 5 copies; Antioxidant (a mixture of 1010 and 168, in a mass ratio of 1:2): 0.2 parts.

[0037] The preparation process of the semi-matte masterbatch in the above embodiments and comparative examples is as follows: Using a twin-screw extruder, the raw materials are added step-by-step according to the formula. PP, PE, and silicone rubber (if any) are fed through feed port 1, while additives and antioxidants are fed through the side feed port. The material is melt-extruded into strips by the twin-screw extruder. The strips are then granulated and dried to produce granular finished products, thus obtaining the semi-matte material. The twin-screw extruder includes 11 sections, where the production temperature of section 1 is 170℃, the production temperature of sections 2-11 is 220℃, the die temperature is 205℃, the rotation speed is controlled at 220-280 r / min, the die head pressure is controlled at 2-5 MPa, and the underwater temperature is controlled at approximately 15℃.

[0038] Using the semi-matte masterbatch obtained in the above embodiments and comparative examples as raw material, it is used as the semi-matte layer of BOPP film at a 100% ratio to prepare semi-matte film material. The semi-matte film is formed after three-layer melt co-extrusion, casting, and biaxial stretching, including an anti-adhesion layer, an antistatic layer, and a semi-matte layer arranged sequentially. The raw material of the anti-adhesion layer is homopolymer polypropylene, the raw material of the antistatic layer is homopolymer polypropylene, and the raw material of the semi-matte layer is 100% semi-matte masterbatch. Film preparation process: The raw materials of each component in each layer are uniformly mixed and then melt co-extruded and cooled to form a thick sheet. The surface layer 1 is extruded through a first auxiliary extruder with a die temperature of 170-240℃; the core layer is extruded through a main extruder with an outlet temperature of 180-240℃. The upper surface layer 2 is extruded through a second auxiliary extruder, with an outlet temperature of 180-240℃ and a die temperature of 240-245℃. Furthermore, the temperature of the cooling casting device is controlled at 45-70℃. In the process of generating a film by sequentially passing the thick sheet formed in step 1 through a longitudinal stretching device and a transverse stretching device for biaxial stretching, the temperature of the rollers in the longitudinal stretching device is controlled as follows: preheating zone 95-100℃, stretching zone 130-145℃, setting zone 95-100℃, stretching ratio 4.5-5.5; the temperature of the rollers in the transverse stretching device is controlled as follows: preheating zone 150-155℃, stretching zone 125-130℃, setting zone 95-100℃, stretching ratio 6-8. The resulting semi-matte film has a thickness of 10-20μm, with an anti-adhesion layer of 2-4μm, an antistatic layer of 6-8μm, and a semi-matte layer of 1-3μm.

[0039] The semi-matte film prepared in the above embodiments exhibits significant hardness and a high degree of stiffness. Furthermore, films from the same location were taken and their matte finish effects were compared, and the roughness, coefficient of friction, and haze of the semi-matte surface were measured. The results are shown in Table 1.

[0040] Table 1

[0041] As shown in Table 1, the semi-matte film prepared in the embodiments of the present invention can be controlled with a haze value in the range of 30-60, making it suitable for use as a semi-matte film. Furthermore, its thickness standard deviation is small, and its thickness uniformity is excellent. A comparison of Examples 4-6 reveals that the haze value of the semi-matte film can be controlled by adjusting the amount of hydrogenated petroleum resin added to the formulation; the more hydrogenated petroleum resin added, the lower the haze value, and vice versa.

[0042] In Comparative Examples 1-3 above, the film thickness uniformity significantly deteriorated after removing the silicone rubber component from the semi-matte masterbatch formulation. Comparative Example 4 prepared a semi-matte film using random copolymer polypropylene and HDPE as the main raw materials at a high ratio of 70 / 30, but the film's hardness and stiffness were significantly worse than those of the embodiments. Comparative Example 5 used random copolymer polypropylene instead of the high-impact polypropylene of this application to manufacture the masterbatch with the same material ratio, but the resulting film was a full-matte film product. Comparative Example 6 significantly changed the ratio of the two main materials (the conventional ratio in the prior art for preparing semi-matte films using random copolymer polypropylene and HDPE) without changing the materials, but the resulting film could not meet the haze requirements of semi-matte films. Comparative Example 7 simply replaced the type of polypropylene based on the prior art, and the resulting film also could not meet the haze requirements of semi-matte films.

Claims

1. A semi-matte masterbatch, characterized in that, Includes the following ingredients and their weight proportions: Impact copolymer PP 45-65 parts HDPE 35-55 parts Antioxidant 0.1-0.8 parts 2-8 parts silicone rubber Additives: 0.1-2 parts.

2. The semi-dull masterbatch according to claim 1, characterized in that, The impact-resistant copolymer PP is a highly crystalline impact-resistant polypropylene with a melt index of 25-60 g / 10min, an ethylene mass fraction of 6-15%, and an ethylene-propylene random copolymer content of 5-25%.

3. The semi-dull masterbatch according to claim 1, characterized in that, The impact-resistant copolymer PP is at least one of BH3900, PP7555KNE2, and EP533N type polypropylene.

4. The semi-dull masterbatch according to claim 1, characterized in that, The melt flow index of the HDPE is 0.05-0.8 g / 10 min.

5. The semi-dull masterbatch according to claim 1, characterized in that, The antioxidant is at least one of BASF1010, BASF168, BASF1141, and BASF1098.

6. The semi-dull masterbatch according to claim 1, characterized in that, The additive is at least one of hydrogenated petroleum resin and erucamide.

7. The semi-dull masterbatch according to claim 1, characterized in that, The silicone rubber is methyl vinyl silicone rubber with a vinyl content of 0.1-0.3 mol% and a molecular weight of 500,000-700,000.

8. The semi-dull masterbatch according to claim 1, characterized in that, The preparation method is as follows: after mixing the raw materials, they are melt-extruded through an extruder, and then stretched, cooled, dried and pelletized to obtain semi-dull masterbatch.

9. A film packaging material, characterized in that, It includes an anti-adhesion layer, an antistatic layer and a semi-matte layer arranged in sequence, wherein the semi-matte layer is formed by melt co-extrusion of the semi-matte masterbatch as described in any one of claims 1-8.

Images