Leather matt transfer film and preparation method thereof

Abstract

The present invention discloses a leather matte transfer film, which is sequentially composed of an upper surface layer (matt layer), a core layer, and a lower surface layer. The upper surface layer comprises the following raw materials in parts by weight: 40-60 parts of isotactic polypropylene, 15-25 parts of high-density polyethylene, 2-5 parts of olefinated fumed silica, 20-35 parts of butyl acrylate, 0.4-0.7 parts of trimethylolpropane triacrylate, 0.04-0.07 parts of azobisisobutyronitrile, 1-3 parts of a dispersant, and 0.1-1.0 parts of an antioxidant; the core layer comprises the following raw materials in parts by weight: 44-56 parts of isotactic polypropylene, 1.1-6.3 parts of an antistatic agent, and 0.2-0.5 parts of a slip agent; and the lower surface layer comprises the following raw materials in parts by weight: 48-65 parts of isotactic polypropylene and 1.0-3.0 parts of fumed silica. The present invention can completely transfer the pattern to the bottom leather, has excellent matting effect and the characteristics of strong toughness, no cracking, and no influence on the texture of the leather surface after transfer. It can also provide the bottom leather with the texture of the transfer film coating, improve the product grade, and is widely used in shoe materials, luggage, clothing leather, etc.

Description

Technical Field

[0001] The invention relates to the technical field of films, and in particular to a leather matt transfer film and a preparation method thereof. Background Art

[0002] In the early days, leather was always brown and black, with monotonous colors and types. With the improvement of people's living standards and the increasing abundance of material life, people's demand for leather fashion and pursuit of high-quality leather products have become more prominent. Not only do they demand perfection in color, color and leather, but they also have higher requirements in energy saving and environmental protection.

[0003] Leather matte transfer films have low gloss, diffuse reflection, and a soft feel, offering good cost-effectiveness. Therefore, they are widely used in car seats, sofas, clothing, luggage, etc. However, existing matte leather transfer films have many bright spots on the surface, resulting in unsatisfactory matte effects and poor mechanical properties. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a leather matte transfer film.

[0005] To solve the above problems, the technical solutions of the present invention are as follows:

[0006] A leather matte transfer film is composed, in sequence, of an upper surface layer (matt layer), a core layer, and a lower surface layer. The upper surface layer comprises the following raw materials in parts by weight: 40-60 parts isotactic polypropylene, 15-25 parts high-density polyethylene, 2-5 parts olefinic fumed silica, 20-35 parts butyl acrylate, 0.4-0.7 parts trimethylolpropane triacrylate, 0.04-0.07 parts azobisisobutyronitrile, 1-3 parts dispersant, and 0.1-1.0 parts antioxidant. The olefinic fumed silica is formed by grafting fumed silica with γ-methacryloyloxypropyltrimethoxysilane.

[0007] The matte layer in the leather matte transfer film described in the present invention is formed by a semi-interpenetrating structure composed of linear isotactic polypropylene, linear high-density polyethylene and cross-linked polyacrylic acid grafted fumed silica through a biaxial stretching process. First, during the biaxial stretching process, due to the existence of the semi-interpenetrating structure, the adjustment space of the high-density polyethylene crystals is limited, the stress effect within the isotactic polypropylene phase domain and the high-density polyethylene phase domain is obvious, the surface roughness is greatly improved, the haze is reduced, and the matte effect is greatly improved; secondly, since the fumed silica is introduced into the semi-interpenetrating network by a grafting method, the presence of chemical bonds increases the stress of the fumed silica in the matte layer and improves the dispersion. During the biaxial stretching process, part of the silica is squeezed to the surface of the matte layer, further increasing the roughness of the surface of the matte layer, thereby improving the matte effect; furthermore, the silica in the matte layer also has a good effect on improving the matte performance of the matte layer.

[0008] The core layer comprises the following raw materials in parts by weight: 44-56 parts of isotactic polypropylene, 1.1-6.3 parts of antistatic agent and 0.2-0.5 parts of lubricant.

[0009] The lower surface layer comprises the following raw materials in parts by weight: 48-65 parts of isotactic polypropylene and 1.0-3.0 parts of fumed silica.

[0010] Furthermore, the melt index of the isotactic polypropylene is 7-10 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.05-0.1 g / 10 min (190° C., 2.16 kg).

[0011] Furthermore, the dispersant is polyethylene wax.

[0012] Furthermore, the antioxidant is antioxidant 1010 or antioxidant 168.

[0013] Furthermore, the antistatic agent is ethoxylated alkylamine.

[0014] Furthermore, the lubricant is ethylene bis stearamide.

[0015] Furthermore, the thickness of the upper surface layer is 1.5-2 μm; the thickness of the core layer is 2-2.5 μm; and the thickness of the lower surface layer is 2-2.5 μm.

[0016] A method for preparing a leather matt transfer film, the specific preparation process is as follows:

[0017] S1: Ultrasonic mixing of fumed silica, γ-methacryloxypropyltrimethoxysilane, sodium lauryl sulfate, and deionized water was performed, and the mixture was reacted at 70-80°C for 12-15 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica.

[0018] S2: Weigh the formulated amount of olefinic fumed silica, butyl acrylate, trimethylolpropane triacrylate, and azobisisobutyronitrile and add them to a ball mill. Grind at 300-500 rpm for 1-2 hours to obtain a premix.

[0019] S3: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the premix in step S1, mix them evenly, add them to the extruder corresponding to the upper surface layer, and heat them into a molten melt;

[0020] S4: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion, and then passing through a casting unit for cooling to form a thick sheet;

[0021] S5: The thick sheet in step S4 is subjected to synchronous biaxial stretching to obtain a leather matte transfer film.

[0022] Furthermore, in step S1, the weight ratio of fumed silica, γ-methacryloxypropyltrimethoxysilane, sodium lauryl sulfate and deionized water is 10:1-1.5:0.3-0.5:100-120.

[0023] Furthermore, in step S3, the extrusion temperature of the extruder corresponding to the upper surface layer is 245-265°C.

[0024] Furthermore, in step S4, the extrusion temperature of the extruder corresponding to the core layer and the lower surface layer is 230-250°C.

[0025] Furthermore, in step S4, the die temperature is 230-270°C.

[0026] Furthermore, in step S4, the cooling temperature of the casting is 20-40°C.

[0027] Furthermore, in step S5, the temperature of the simultaneous biaxial stretching is 110-135° C., and the stretching ratio is 5-8 times.

[0028] Beneficial technical effects,

[0029] 1. The leather matte transfer film prepared by the present invention can completely transfer the pattern to the bottom leather, has excellent matte effect and the characteristics of strong toughness, no cracking, and no influence on the texture of the leather surface after transfer. It can also provide the texture of the transfer film coating for the bottom leather, improve the product grade, and is widely used in shoes, bags, clothing leather, etc.

[0030] 2. The leather matt transfer film prepared by the present invention has good flexibility, is resistant to repeated bending, and is suitable for soft leather substrates.

[0031] 3. The matte layer in the leather matte transfer film prepared by the present invention has uniform surface roughness, no bright spots, strong oxidation resistance, and will not yellow during long-term use. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] Example 1

[0034] The utility model relates to a leather matt transfer film, which is composed of an upper surface layer (matt layer), a core layer and a lower surface layer in sequence.

[0035] The upper surface layer comprises the following raw materials in parts by weight: 40 parts of isotactic polypropylene, 15 parts of high-density polyethylene, 2 parts of olefinic fumed silica, 20 parts of butyl acrylate, 0.4 parts of trimethylolpropane triacrylate, 0.04-0.07 parts of azobisisobutyronitrile, 1 part of polyethylene wax, and 0.1 parts of antioxidant;

[0036] The core layer comprises the following raw materials in parts by weight: 44 parts of isotactic polypropylene, 1.1 parts of ethoxylated alkylamine and 0.2 parts of ethylene bis stearamide.

[0037] The lower surface layer comprises the following raw materials in parts by weight: 48 parts of isotactic polypropylene and 1.0 part of fumed silica.

[0038] The melt index of the isotactic polypropylene is 7 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.05 g / 10 min (190° C., 2.16 kg).

[0039] A method for preparing a leather matt transfer film, the specific preparation process is as follows:

[0040] S1: 10 parts of fumed silica, 1 part of γ-methacryloxypropyltrimethoxysilane, 0.3 parts of sodium lauryl sulfate and 100 parts of deionized water were ultrasonically mixed by weight, and reacted at 70°C for 12 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica;

[0041] S2: Weigh the formulated amount of olefinic fumed silica, butyl acrylate, trimethylolpropane triacrylate, and azobisisobutyronitrile and add them to a ball mill, and grind at 300 rpm for 1 hour to obtain a premix;

[0042] S3: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the premix in step S1. After mixing evenly, add them to the extruder corresponding to the upper surface layer. The extrusion temperature is 24° C. and heated to a molten melt.

[0043] S4: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution at an extrusion temperature of 230°C, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion at a die temperature of 230°C, and then passing through a casting cooling unit at a cooling temperature of 20-4°C to form a thick sheet;

[0044] S5: The thick sheet prepared in step S4 is subjected to synchronous biaxial stretching at a stretching temperature of 110° C. and a stretching ratio of 7 to obtain a leather matte transfer film.

[0045] Example 2

[0046] The utility model relates to a leather matt transfer film, which is composed of an upper surface layer (matt layer), a core layer and a lower surface layer in sequence.

[0047] The upper surface layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 20 parts of high-density polyethylene, 3.5 parts of olefinic fumed silica, 27 parts of butyl acrylate, 0.5 parts of trimethylolpropane triacrylate, 0.05 parts of azobisisobutyronitrile, 1-3 parts of polyethylene wax, and 0.5 parts of antioxidant 1010;

[0048] The core layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 3.5 parts of ethoxylated alkylamine and 0.4 parts of ethylene bis stearamide.

[0049] The lower surface layer comprises the following raw materials in parts by weight: 56 parts of isotactic polypropylene and 2 parts of fumed silica.

[0050] The melt index of the isotactic polypropylene is 8 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.07 g / 10 min (190° C., 2.16 kg).

[0051] A method for preparing a leather matt transfer film, the specific preparation process is as follows:

[0052] S1: 10 parts of fumed silica, 1.2 parts of γ-methacryloxypropyltrimethoxysilane, 0.4 parts of sodium lauryl sulfate, and 110 parts of deionized water were ultrasonically mixed by weight, and reacted at 75°C for 13 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica;

[0053] S2: Weigh the formulated amount of olefinic fumed silica, butyl acrylate, trimethylolpropane triacrylate, and azobisisobutyronitrile and add them to a ball mill and grind at 400 rpm for 1.5 hours to obtain a premix;

[0054] S3: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the premix in step S1. After mixing evenly, add them to the extruder corresponding to the upper surface layer and heat them into a molten melt at an extrusion temperature of 255°C.

[0055] S4: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution at an extrusion temperature of 240°C, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion at a die temperature of 250°C, and then passing through a casting cooling unit at a cooling temperature of 30°C to form a thick sheet;

[0056] S5: The thick sheet in step S4 is subjected to synchronous biaxial stretching at a stretching temperature of 125° C. and a stretching ratio of 7 to obtain a leather matte transfer film.

[0057] Example 3

[0058] The utility model relates to a leather matt transfer film, which is composed of an upper surface layer (matt layer), a core layer and a lower surface layer in sequence.

[0059] The upper surface layer comprises the following raw materials in parts by weight: 60 parts of isotactic polypropylene, 25 parts of high-density polyethylene, 5 parts of olefinated fumed silica, 35 parts of butyl acrylate, 0.7 parts of trimethylolpropane triacrylate, 0.07 parts of azobisisobutyronitrile, 3 parts of polyethylene wax, and 1681.0 parts of antioxidant;

[0060] The core layer comprises the following raw materials in parts by weight: 56 parts of isotactic polypropylene, 6.3 parts of ethoxylated alkylamine and 0.5 parts of ethylene bis stearamide.

[0061] The lower surface layer comprises the following raw materials in parts by weight: 65 parts of isotactic polypropylene and 3.0 parts of fumed silica.

[0062] The melt index of the isotactic polypropylene is 10 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.1 g / 10 min (190° C., 2.16 kg).

[0063] A method for preparing a leather matt transfer film, the specific preparation process is as follows:

[0064] S1: 10 parts of fumed silica, 1.5 parts of γ-methacryloxypropyltrimethoxysilane, 0.5 parts of sodium lauryl sulfate, and 120 parts of deionized water were ultrasonically mixed by weight, and reacted at 80°C for 15 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica;

[0065] S2: Weigh the formulated amount of olefinic fumed silica, butyl acrylate, trimethylolpropane triacrylate, and azobisisobutyronitrile and add them to a ball mill, and grind at 500 rpm for 2 hours to obtain a premix;

[0066] S3: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the premix described in step S1. After mixing evenly, add them to the extruder corresponding to the upper surface layer and heat them into a molten melt at an extrusion temperature of 265°C.

[0067] S4: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution at an extrusion temperature of 250°C, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion at a die temperature of 270°C, and then passing through a casting cooling unit at a cooling temperature of 40°C to form a thick sheet;

[0068] S5: The thick sheet in step S4 is subjected to synchronous biaxial stretching at a stretching temperature of 135° C. and a stretching ratio of 7 to obtain a leather matte transfer film.

[0069] Comparative Example 1

[0070] The utility model relates to a leather matt transfer film, which is composed of an upper surface layer (matt layer), a core layer and a lower surface layer in sequence.

[0071] The upper surface layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 20 parts of high-density polyethylene, 5 parts of olefinated fumed silica, 1-3 parts of polyethylene wax and 10100.5 parts of antioxidant;

[0072] The core layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 3.5 parts of ethoxylated alkylamine and 0.4 parts of ethylene bis stearamide.

[0073] The lower surface layer comprises the following raw materials in parts by weight: 56 parts of isotactic polypropylene and 2 parts of fumed silica.

[0074] The melt index of the isotactic polypropylene is 8 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.07 g / 10 min (190° C., 2.16 kg).

[0075] A method for preparing a leather matt transfer film, the specific preparation process is as follows:

[0076] S1: 10 parts of fumed silica, 1.2 parts of γ-methacryloxypropyltrimethoxysilane, 0.4 parts of sodium lauryl sulfate, and 110 parts of deionized water were ultrasonically mixed by weight, and reacted at 75°C for 13 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica;

[0077] S2: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, olefinic fumed silica, dispersant, and antioxidant and add them to the extruder corresponding to the upper surface layer. The extrusion temperature is 255°C and heated to a molten melt.

[0078] S3: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution at an extrusion temperature of 240°C, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion at a die temperature of 250°C, and then passing through a casting cooling unit at a cooling temperature of 30°C to form a thick sheet;

[0079] S4: The thick sheet in step S4 is subjected to synchronous biaxial stretching at a stretching temperature of 125° C. and a stretching ratio of 7 to obtain a leather matte transfer film.

[0080] Comparative Example 2

[0081] The utility model relates to a leather matt transfer film, which is composed of an upper surface layer (matt layer), a core layer and a lower surface layer in sequence.

[0082] The upper surface layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 20 parts of high-density polyethylene, 1-3 parts of polyethylene wax, and 10100.5 parts of antioxidant;

[0083] The core layer comprises the following raw materials in parts by weight: 50 parts of isotactic polypropylene, 3.5 parts of ethoxylated alkylamine and 0.4 parts of ethylene bis stearamide.

[0084] The lower surface layer comprises the following raw materials in parts by weight: 56 parts of isotactic polypropylene and 2 parts of fumed silica.

[0085] The melt index of the isotactic polypropylene is 8 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.07 g / 10 min (190° C., 2.16 kg).

[0086] S1: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the extruder corresponding to the upper surface layer. The extrusion temperature is 255°C and heated to a molten melt.

[0087] S2: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution at an extrusion temperature of 240°C, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion at a die temperature of 250°C, and then passing through a casting cooling unit at a cooling temperature of 30°C to form a thick sheet;

[0088] S3: The thick sheet in step S4 is subjected to synchronous biaxial stretching at a stretching temperature of 125° C. and a stretching ratio of 7 to obtain a leather matte transfer film.

[0089] Performance Testing

[0090] Haze test: performed according to GB / T2410-2008. The test results are shown in Table 1.

[0091] Tensile strength test: performed in accordance with GB / T10004-2008. The test results are shown in Table 1.

[0092] Table 1 Performance test results of Examples 1-3 and Comparative Examples 1-2

[0093]

[0094] Data analysis: From the performance test results in Table 1, it can be seen that the leather matte transfer film prepared by the present invention has excellent matte effect, good flexibility, resistance to repeated bending, and is suitable for soft leather substrates.

[0095] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A leather matt transfer film, characterized in that: The leather matte transfer film is composed of an upper surface layer, a core layer and a lower surface layer in sequence. The upper surface layer includes the following raw materials in parts by weight: 40-60 parts of isotactic polypropylene, 15-25 parts of high-density polyethylene, 2-5 parts of olefinic fumed silica, 20-35 parts of butyl acrylate, 0.4-0.7 parts of trimethylolpropane triacrylate, 0.04-0.07 parts of azobisisobutyronitrile, 1-3 parts of a dispersant, and 0.1-1.0 parts of an antioxidant; the core layer includes the following raw materials in parts by weight: 44-56 parts of isotactic polypropylene, 1.1-6.3 parts of an antistatic agent, and 0.2-0.5 parts of a slip agent; the lower surface layer includes the following raw materials in parts by weight: 48-65 parts of isotactic polypropylene and 1.0-3.0 parts of fumed silica; the olefinic fumed silica is formed by grafting fumed silica with γ-methacryloyloxypropyltrimethoxysilane.

2. The leather matte transfer film according to claim 1, characterized in that: The melt index of the isotactic polypropylene is 7-10 g / 10 min (190° C., 2.16 kg), and the melt index of the high-density polyethylene is 0.05-0.1 g / 10 min (190° C., 2.16 kg).

3. The leather matte transfer film according to claim 1, characterized in that: The dispersant is polyethylene wax; the antioxidant is antioxidant 1010 or antioxidant 168; the antistatic agent is ethoxylated alkylamine; and the lubricant is ethylene bis stearamide.

4. The leather matte transfer film according to claim 1, characterized in that: The thickness of the upper surface layer is 1.5-2 μm; the thickness of the core layer is 2-2.5 μm; and the thickness of the lower surface layer is 2-2.5 μm.

5. A method for preparing a leather matt transfer film according to any one of claims 1 to 4, characterized in that: The specific preparation process is as follows: S1: Ultrasonic mixing of fumed silica, γ-methacryloxypropyltrimethoxysilane, sodium lauryl sulfate, and deionized water was performed, and the mixture was reacted at 70-80°C for 12-15 hours. After the reaction, the mixture was washed and dried to obtain olefinated fumed silica. S2: Weigh the formulated amount of olefinic fumed silica, butyl acrylate, trimethylolpropane triacrylate, and azobisisobutyronitrile and add them to a ball mill. Grind at 300-500 rpm for 1-2 hours to obtain a premix. S3: Weigh the formulated amount of copolymerized polypropylene, high-density polyethylene, dispersant, and antioxidant and add them to the premix in step S1, mix them evenly, add them to the extruder corresponding to the upper surface layer, and heat them into a molten melt; S4: adding the core layer and lower surface layer raw materials according to the formula amount into the corresponding extruder to melt into a solution, filtering the melt and the melt in step S2 through a filter, and then conveying them to a T-die for co-extrusion, and then passing through a casting unit for cooling to form a thick sheet; S5: The thick sheet in step S4 is subjected to synchronous biaxial stretching to obtain a leather matte transfer film.

6. The method for preparing a leather matt transfer film according to claim 5, wherein: In step S1, the weight ratio of fumed silica, γ-methacryloxypropyltrimethoxysilane, sodium lauryl sulfate and deionized water is 10:1-1.5:0.3-0.5:100-120.

7. The method for preparing a leather matt transfer film according to claim 5, wherein: The extrusion temperature of the extruder corresponding to the upper surface layer in step S3 is 245-265° C.; the extrusion temperature of the extruder corresponding to the core layer and the lower surface layer in step S4 is 230-250° C.

8. The method for preparing a leather matt transfer film according to claim 5, wherein: The die temperature in step S4 is 230-270°C.

9. The method for preparing a leather matt transfer film according to claim 5, wherein: The cooling temperature of the slab in step S4 is 20-40°C.

10. The method for preparing a leather matt transfer film according to claim 5, characterized in that: In step S5, the temperature of the simultaneous biaxial stretching is 110-135° C., and the stretching ratio is 5-8 times.

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