Preparation method of TPU (thermoplastic polyurethane) and PVC (polyvinyl chloride) composite fabric

Abstract

The invention discloses a preparation method of a TPU (thermoplastic polyurethane) and PVC (polyvinyl chloride) composite fabric, and relates to the field of fabrics. Thermoplastic polyurethane, polyvinyl chloride and a reactive compatibilizer are blended, dicumyl peroxide is introduced to serve as a cross-linking agent, the interfacial compatibility and processing stability of TPU / PVC are remarkably improved, then a film is prepared through a four-roll calendering technology, the film is attached to a polyester non-woven fabric base cloth coated with ultraviolet curing glue, and the film is formed. And the high-performance composite fabric is obtained after ultraviolet irradiation curing. The composite fabric obtained by the invention has excellent mechanical properties and bonding strength.

Description

Technical Field

[0001] The present invention relates to the field of fabrics, and in particular to a method for preparing a TPU and PVC composite fabric. Background Art

[0002] Composite fabrics are a new type of fabric created by combining two or more fabrics with different properties through a specific process. They combine the advantages of each component fabric to achieve superior performance. For example, a waterproof and breathable membrane laminated to a fabric not only provides waterproofing but also allows perspiration to escape, keeping the body dry and comfortable. Laying a thermal insulation fiber layer to a fabric enhances its warmth retention. Composite fabrics are widely used in outdoor clothing, sports equipment, medical protective equipment, and other fields, meeting the demand for functional fabrics in various scenarios and improving product quality and user experience.

[0003] Publication No. CN102729559B discloses a method for preparing a TPU and PVC blended improved composite fabric. The method first blends TPU and PVC so that the two can give full play to their respective characteristics and achieve the purpose of complementary advantages. The TPU and PVC blended film is obtained by calendering using a four-roll calendering method, and then the TPU and PVC blended film is online bonded with the glued base fabric on a calender to obtain a TPU and PVC blended improved composite fabric. However, the above composite fabric still has some shortcomings: due to the large difference in molecular structure between TPU and PVC, simple physical blending is difficult to achieve good interfacial compatibility, resulting in unstable mechanical properties of the composite fabric and insufficient interfacial bonding strength. The solvent-based glue used contains volatile organic compounds and requires high-temperature drying during the bonding process, which not only consumes a lot of energy but also causes environmental pollution. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a TPU and PVC composite fabric to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a TPU and PVC composite fabric, comprising the following preparation steps:

[0006] (1) Thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer were mixed, and then mixed in a high-speed mixer at a speed of 800±50 rpm for 10±1 minutes, and then dried at a temperature of 80±1°C for 2±0.2 hours;

[0007] (2) adding the mixture obtained in step (1), a calcium zinc heat stabilizer, and a crosslinking agent, dicumyl peroxide, into an internal mixer, and mixing for 15±1 minutes at a temperature of 130-135° C. and a rotor speed of 40±2 rpm to form a crosslinked blend;

[0008] (3) feeding the cross-linked blend obtained in step (2) into a four-roll calender via a conveyor belt for film calendering, and calendering the film into a film with a thickness of 0.2±0.02 mm. The required thickness specification is set by adjusting the distance between the rollers;

[0009] (4) mixing an acrylate monomer and a photoinitiator TPO to prepare a UV-curable glue, and then uniformly coating the UV-curable glue on the surface of the film obtained in step (3) by an automatic scraper coating head, wherein the coated UV-curable glue has a thickness of 50±5 μm;

[0010] (5) The polyester non-woven fabric base and the film coated with UV curing glue are laminated at the exit of the four-roll calender and the power density is 800±50mJ / cm 2 The fabric is irradiated with an ultraviolet lamp for 3±0.3 seconds to cure, and then introduced into a cooling device to be cooled to 30±2°C to form a composite fabric.

[0011] Furthermore, the reactive compatibilizer in step (1) is prepared by dissolving SEBS particles in a toluene solution, heating to 80±1° C., then adding glycidyl methacrylate and benzoyl peroxide initiator, mixing and reacting for 2±0.2 hours, using ethanol as a precipitant to precipitate the product, and filtering and drying the product to obtain the reactive compatibilizer.

[0012] Furthermore, the mass ratio of SEBS particles, toluene solution, glycidyl methacrylate, benzoyl peroxide initiator, and ethanol is 100:500-600:8-12:0.08-0.12:1500-2000, and the particle size of the SEBS particles is 0.5-2.0 mm.

[0013] Furthermore, in step (1), the mass ratio of thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer is 70:20-30:3-7.

[0014] Furthermore, in step (2), the mass ratio of the mixture obtained in step (1), the calcium zinc heat stabilizer, and the cross-linking agent dicumyl peroxide is: 100:0.5-1.5:0.3-0.7.

[0015] Furthermore, the temperatures of the four rollers of the four-roll calender in step (3) are: 135±2°C for the first roller, 140±2°C for the second roller, 145±2°C for the third roller, and 140±2°C for the fourth roller.

[0016] Furthermore, in step (4), the mass ratio of the acrylate monomer to the photoinitiator TPO is 90:5-10.

[0017] Furthermore, the acrylate monomer in step (4) is a mixture of methyl methacrylate and isooctyl acrylate in a mass ratio of 5-7:3.

[0018] Furthermore, the lamination pressure in step (5) is 0.5±0.05 MPa.

[0019] Furthermore, the thickness of the polyester non-woven fabric base fabric in step (5) is 0.3±0.03 mm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. In the present invention, during the preparation of the reactive compatibilizer, benzoyl peroxide decomposes upon heating to generate benzoyloxy radicals. These benzoyloxy radicals first attack the ethylene-butylene segments in SEBS, generating the macromolecular free radical SEBS·. Subsequently, the macromolecular free radical SEBS· undergoes a grafting reaction with the methacrylate double bond of glycidyl methacrylate to form a graft copolymer containing epoxy groups (i.e., the reactive compatibilizer). During the subsequent preparation process, the styrene segments of the reactive compatibilizer physically entangle with the chlorine atoms of PVC (polyvinyl chloride) via van der Waals forces. Furthermore, amino groups of TPU (thermoplastic polyurethane) and the epoxy groups of the reactive compatibilizer undergo a ring-opening reaction under the high temperature of an internal mixer, forming ether bonds, effectively enhancing the interfacial compatibility between TPU and PVC.

[0022] 2. In the present invention, under the irradiation of an ultraviolet lamp, the photoinitiator TPO absorbs ultraviolet photons to generate highly active phosphoryl radicals. The phosphoryl radicals first attack the double bonds of the acrylate monomer, triggering a chain polymerization reaction, and then forming a three-dimensional cross-linked network. This three-dimensional cross-linked network can penetrate into the fiber pores of the polyester non-woven fabric base and anchor the fibers, thereby improving the bonding strength between the polyester non-woven fabric base and the film. In addition, by directly applying ultraviolet curing glue and laminating at the outlet of the four-roll calender, the residual heat of the film is used to reduce the viscosity of the glue, promoting the penetration and diffusion of the ultraviolet curing glue into the polyester non-woven fabric base, and at the same time combining ultraviolet irradiation to achieve rapid curing, which not only ensures the bonding strength but also greatly improves the production efficiency. DETAILED DESCRIPTION

[0023] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0024] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0025] The testing methods for the various parameters of the materials obtained in the following examples and comparative examples are as follows: Tensile properties were tested in accordance with GB / T1040.3-2006 using a universal materials testing machine at 23±2°C and 50% RH. The specimen dimensions were 150 mm x 25 mm, and the tensile speed was 100 mm / min. The maximum load and elongation at break were recorded, and the tensile strength and elongation at break were calculated. Lamination strength was tested in accordance with GB / T 2791-1995 using an electronic tensile testing machine at a speed of 300 mm / min, performing an 180° peel test. The average peel force was recorded and converted to N / cm.

[0026] Example 1

[0027] (1) SEBS particles were dissolved in a toluene solution and heated to 79°C. Glycidyl methacrylate and benzoyl peroxide initiator were then added. After mixing and reacting for 1.8 hours, ethanol was used as a precipitant to precipitate the product. The product was filtered and dried to obtain a reactive compatibilizer. The mass ratio of SEBS particles, toluene solution, glycidyl methacrylate, benzoyl peroxide initiator, and ethanol was 100:500:8:0.08:1500, and the particle size of the SEBS particles was 0.5 mm.

[0028] Thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer were mixed, then mixed in a high-speed mixer at a speed of 750 rpm for 9 minutes, and then dried at a temperature of 79° C. for 1.8 hours; the mass ratio of thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer was 70:20:3.

[0029] (2) adding the mixture obtained in step (1), a calcium zinc heat stabilizer, and a crosslinking agent, dicumyl peroxide, into an internal mixer, and mixing them at a temperature of 130° C. and a rotor speed of 38 rpm for 14 minutes to form a crosslinked blend; the mass ratio of the mixture obtained in step (1), the calcium zinc heat stabilizer, and the crosslinking agent, dicumyl peroxide, is 100:0.5:0.3.

[0030] (3) The cross-linked blend obtained in step (2) is sent to a four-roll calender via a conveyor belt for film calendering, and the film is calendered into a film with a thickness of 0.18 mm. The required thickness specification is set by adjusting the distance between the rollers; the temperatures of the four rollers of the four-roll calender are: 133°C for the first roller, 138°C for the second roller, 143°C for the third roller, and 138°C for the fourth roller.

[0031] (4) Mixing an acrylate monomer and a photoinitiator TPO to form a UV-curable glue, and then uniformly coating the UV-curable glue on the surface of the film obtained in step (3) using an automatic scraper coating head, wherein the coated UV-curable glue has a thickness of 45 μm; the mass ratio of the acrylate monomer to the photoinitiator TPO is 90:5. The acrylate monomer is a mixture of methyl methacrylate and isooctyl acrylate in a mass ratio of 5:3.

[0032] (5) The polyester non-woven fabric with a thickness of 0.27 mm and the film coated with UV curing glue were laminated at the exit of a four-roll calender with a lamination pressure of 0.45 MPa. The power density was 750 mJ / cm 2 The fabric was cured by irradiating it with an ultraviolet lamp for 2.7 seconds, and then introduced into a cooling device to be cooled to 28°C to form a composite fabric.

[0033] Example 2

[0034] (1) SEBS particles were dissolved in a toluene solution and heated to 80°C. Glycidyl methacrylate and benzoyl peroxide initiator were then added. After mixing and reacting for 2 hours, ethanol was used as a precipitant to precipitate the product. The product was filtered and dried to obtain a reactive compatibilizer. The mass ratio of SEBS particles, toluene solution, glycidyl methacrylate, benzoyl peroxide initiator, and ethanol was 100:550:10:0.10:1750, and the particle size of the SEBS particles was 1.25 mm.

[0035] Thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer were mixed, then mixed in a high-speed mixer at a speed of 800 rpm for 10 minutes, and then dried at a temperature of 80° C. for 2 hours; the mass ratio of thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer was 70:25:5.

[0036] (2) adding the mixture obtained in step (1), a calcium zinc heat stabilizer, and a crosslinking agent, dicumyl peroxide, into an internal mixer, and mixing them at a temperature of 132.5° C. and a rotor speed of 40 rpm for 15 minutes to form a crosslinked blend; the mass ratio of the mixture obtained in step (1), the calcium zinc heat stabilizer, and the crosslinking agent, dicumyl peroxide, is 100:1.0:0.5.

[0037] (3) The cross-linked blend obtained in step (2) is sent to a four-roll calender via a conveyor belt for film calendering, and the film is calendered into a film with a thickness of 0.20 mm. The required thickness specification is set by adjusting the distance between the rollers; the temperatures of the four rollers of the four-roll calender are: 135°C for the first roller, 140°C for the second roller, 145°C for the third roller, and 140°C for the fourth roller.

[0038] (4) Mixing an acrylate monomer and a photoinitiator TPO to form a UV-curable glue, and then uniformly coating the UV-curable glue on the surface of the film obtained in step (3) using an automatic scraper coating head, wherein the coated UV-curable glue has a thickness of 50 μm; the mass ratio of the acrylate monomer to the photoinitiator TPO is 90:7.5. The acrylate monomer is a mixture of methyl methacrylate and isooctyl acrylate in a mass ratio of 6:3.

[0039] (5) The polyester non-woven fabric with a thickness of 0.30 mm and the film coated with UV curing glue were laminated at the exit of a four-roll calender with a laminating pressure of 0.50 MPa. The power density was 800 mJ / cm 2 The fabric is irradiated with an ultraviolet lamp for 3 seconds to cure, and then introduced into a cooling device to be cooled to 30°C to form a composite fabric.

[0040] Example 3

[0041] (1) SEBS particles were dissolved in a toluene solution and heated to 81°C. Glycidyl methacrylate and benzoyl peroxide initiator were then added. After mixing and reacting for 2.2 hours, ethanol was used as a precipitant to precipitate the product. The product was filtered and dried to obtain a reactive compatibilizer. The mass ratio of SEBS particles, toluene solution, glycidyl methacrylate, benzoyl peroxide initiator, and ethanol was 100:600:12:0.12:2000, and the particle size of the SEBS particles was 2.0 mm.

[0042] Thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer were mixed, then mixed in a high-speed mixer at a speed of 850 rpm for 11 minutes, and then dried at a temperature of 81° C. for 2.2 hours; the mass ratio of thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer was 70:30:7.

[0043] (2) adding the mixture obtained in step (1), a calcium zinc heat stabilizer, and a crosslinking agent, dicumyl peroxide, into an internal mixer, and mixing them at a temperature of 135° C. and a rotor speed of 42 rpm for 16 minutes to form a crosslinked blend; the mass ratio of the mixture obtained in step (1), the calcium zinc heat stabilizer, and the crosslinking agent, dicumyl peroxide, is 100:1.5:0.7.

[0044] (3) The cross-linked blend obtained in step (2) is sent to a four-roll calender via a conveyor belt for film calendering, and the film is calendered into a film with a thickness of 0.22 mm. The required thickness specification is set by adjusting the distance between the rollers; the temperatures of the four rollers of the four-roll calender are: 137°C for the first roller, 142°C for the second roller, 147°C for the third roller, and 142°C for the fourth roller.

[0045] (4) Mixing an acrylate monomer and a photoinitiator TPO to form a UV-curable glue, and then uniformly coating the UV-curable glue on the surface of the film obtained in step (3) using an automatic scraper coating head, wherein the coated UV-curable glue has a thickness of 55 μm; the mass ratio of the acrylate monomer to the photoinitiator TPO is 90:10. The acrylate monomer is a mixture of methyl methacrylate and isooctyl acrylate in a mass ratio of 7:3.

[0046] (5) The polyester non-woven fabric with a thickness of 0.33 mm and the film coated with UV curing glue were laminated at the exit of a four-roll calender with a laminating pressure of 0.55 MPa. The power density was 850 mJ / cm 2 The fabric was cured by irradiating it with an ultraviolet lamp for 3.3 seconds, and then introduced into a cooling device to be cooled to 32°C to form a composite fabric.

[0047] Comparative Example 1

[0048] The only difference between Comparative Example 1 and Example 1 is that no reactive compatibilizer is added.

[0049] Comparative Example 2

[0050] The only difference between Comparative Example 2 and Example 1 is that no photoinitiator TPO is added.

[0051] Comparative Example 3

[0052] The only difference between Comparative Example 3 and Example 1 is that conventional water-based polyurethane glue is used instead of UV curing glue, and it needs to be dried at 80° C. for 5 minutes to evaporate the solvent.

[0053] Comparative Example 4

[0054] The only difference between Comparative Example 4 and Example 1 is that ordinary SEBS is used as the compatibilizer instead of the reactive compatibilizer.

[0055] Table 1 below shows the performance analysis results of the samples prepared in the examples of the present invention and the comparative examples.

[0056] Test indicators Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile strength (MPa) 22.3 23.5 21.8 15.2 14.8 19.2 17.6 Elongation at break (%) 320 335 305 250 260 290 270 Bonding strength (N / cm) 6.8 7.2 6.5 3.2 2.1 5.3 4.8

[0057] Table 1

[0058] The experimental data from the Examples and Comparative Examples indicate that the styrene chain segments of the reactive compatibilizer of the present invention form physical entanglements with the chlorine atoms of PVC through van der Waals forces. Furthermore, the amino groups of TPU and the epoxy groups of the reactive compatibilizer undergo a ring-opening reaction under the high temperature of the internal mixer to form ether bonds, effectively enhancing the interfacial compatibility between TPU and PVC, thereby improving the tensile strength and elongation at break of the fabric. Under ultraviolet light irradiation, the photoinitiator TPO triggers a chain polymerization reaction of the acrylate monomers, forming a three-dimensional cross-linked network. This three-dimensional cross-linked network can penetrate into the fiber pores of the polyester non-woven fabric base and anchor the fibers, thereby improving the bonding strength between the polyester non-woven fabric base and the film.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for preparing a TPU and PVC composite fabric, characterized in that: The method comprises the following preparation steps: (1) Thermoplastic polyurethane, polyvinyl chloride, and reactive compatibilizer were mixed, and then mixed in a high-speed mixer at a speed of 800±50 rpm for 10±1 minutes, and then dried at a temperature of 80±1°C for 2±0.2 hours; (2) adding the mixture obtained in step (1), a calcium zinc heat stabilizer, and a crosslinking agent, dicumyl peroxide, into an internal mixer, and mixing for 15±1 minutes at a temperature of 130-135° C. and a rotor speed of 40±2 rpm to form a crosslinked blend; (3) feeding the cross-linked blend obtained in step (2) into a four-roll calender via a conveyor belt for film calendering, and calendering the film into a film with a thickness of 0.2±0.02 mm. The required thickness specification is set by adjusting the distance between the rollers; (4) mixing an acrylate monomer and a photoinitiator TPO to prepare a UV-curable glue, and then uniformly coating the UV-curable glue on the surface of the film obtained in step (3) by an automatic scraper coating head, wherein the coated UV-curable glue has a thickness of 50±5 μm; (5) The polyester non-woven fabric base and the film coated with UV curing glue are laminated at the exit of the four-roll calender and the power density is 800±50mJ / cm 2 The fabric is irradiated with an ultraviolet lamp for 3±0.3 seconds to cure, and then introduced into a cooling device to be cooled to 30±2°C to form a composite fabric.

2. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: The reactive compatibilizer in step (1) is prepared by dissolving SEBS particles in a toluene solution, heating the solution to 80±1° C., adding glycidyl methacrylate and benzoyl peroxide as an initiator, and reacting the mixture for 2±0.2 hours. Then, ethanol is used as a precipitant to precipitate the product, and the product is filtered and dried to obtain the reactive compatibilizer.

3. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: The mass ratio of SEBS particles, toluene solution, glycidyl methacrylate, benzoyl peroxide initiator, and ethanol is 100:500-600:8-12:0.08-0.12:1500-2000, and the particle size of the SEBS particles is 0.5-2.0 mm.

4. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: In step (1), the mass ratio of thermoplastic polyurethane, polyvinyl chloride and reactive compatibilizer is 70:20-30:3-7.

5. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: In step (2), the mass ratio of the mixture obtained in step (1), the calcium zinc heat stabilizer, and the crosslinking agent dicumyl peroxide is: 100:0.5-1.5:0.3-0.

7.

6. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: The temperatures of the four rollers of the four-roll calender in step (3) are: 135±2°C for the first roller, 140±2°C for the second roller, 145±2°C for the third roller, and 140±2°C for the fourth roller.

7. The method for preparing a TPU and PVC composite fabric according to claim 1, characterized in that: In step (4), the mass ratio of the acrylate monomer to the photoinitiator TPO is 90:5-10.

8. The method for preparing a TPU and PVC composite fabric according to claim 1, characterized in that: The acrylate monomer in step (4) is a mixture of methyl methacrylate and isooctyl acrylate in a mass ratio of 5-7:

3.

9. The method for preparing a TPU and PVC composite fabric according to claim 1, wherein: The lamination pressure in step (5) is 0.5±0.05 MPa.

10. The method for preparing a TPU and PVC composite fabric according to claim 1, characterized in that: The thickness of the polyester non-woven fabric base fabric in step (5) is 0.3±0.03 mm.