TPU / PVC modified film, space composite material and preparation method of TPU / PVC modified film

Abstract

The invention relates to a TPU / PVC (thermoplastic polyurethane / polyvinyl chloride) modified film as well as a preparation method and application thereof. The TPU / PVC modified film comprises the following components in parts by mass: 50-75 parts of polyether type TPU; 25 to 50 parts by mass of PVC resin; 20-35 parts by mass of a plasticizer; 1-2 parts by mass of a composite calcium-zinc stabilizer; 0.4 to 0.6 part by mass of an anti-ultraviolet light absorber; 0.2 to 0.5 part by mass of a composite antioxidant; 0-0.2 part by mass of a lubricant; in the preparation process, the PVC and the TPU are fused; a structure with TPU as a continuous phase and plasticized PVC as a dispersed phase is formed. The TPU / PVC modified space composite material is of a sandwich structure and comprises a surface layer, a bottom layer and a middle layer, wherein the surface layer and the bottom layer are TPU / PVC modified films, and the middle layer is space mesh cloth. Compared with the prior art, the TPU / PVC modified space composite material has the advantages of light smell, good flexibility, low temperature resistance, weather resistance and hydrolysis resistance.

Description

Technical Field

[0001] This invention relates to the field of new materials, specifically to a TPU / PVC modified film, a space composite material, and a method for preparing the same. Background Technology

[0002] PVC space composite materials employ a special space mesh structure, with a surface coated with PU or PVC paste and laminated with a PVC film layer. Commonly available PVC space composite materials are popular due to their high cost-effectiveness and good overall performance; however, they suffer from a strong odor, plasticizer leaching with prolonged use, poor low-temperature folding resistance leading to cracking and air leakage, or whitening of creases affecting aesthetics. TPU space composite materials, on the other hand, have drawbacks such as high TPU material price, poor hydrolysis resistance, susceptibility to yellowing outdoors, and low production capacity. Summary of the Invention

[0003] In view of the above problems, this application provides a flexible space composite material with high strength, good weather resistance, excellent hydrolysis resistance, high airtightness, and folding resistance.

[0004] The first aspect of this application provides a TPU / PVC modified film with a thickness of 0.50-0.65 mm, comprising the following components: 50-75 parts by weight of polyether-type TPU; 25-50 parts by weight of PVC resin; 20-35 parts by weight of plasticizer; 1-2 parts by weight of composite calcium-zinc stabilizer; 0.4-0.6 parts by weight of UV absorber; 0.2-0.5 parts by weight of composite antioxidant; and 0-0.2 parts by weight of lubricant.

[0005] Unlike existing technologies, the above-mentioned technical solution provides a TPU / PVC modified film, which is mainly composed of polyether-type TPU raw materials. The film produced has good flexibility, good low-temperature resistance, and a longer service life due to folding. At the same time, blending with PVC resin not only reduces costs but also effectively improves the material's resistance to yellowing and hydrolysis. The overall formula maintains softness while reducing plasticizers, effectively reducing migration and maintaining the material's good performance. In addition, the formula contains little or no lubricant, which ensures smooth film production and effectively avoids lubricant precipitation, which is beneficial for subsequent high-temperature and adhesive processing.

[0006] Furthermore, the total amount of the polyether-type TPU and PVC resin is 100 parts by weight.

[0007] Furthermore, the polyether-type TPU has a hardness of 70-88A. This hardness level provides the polyether-type TPU with good flexibility, toughness, and mechanical strength. It can provide sufficient "skeleton" support, making the film less prone to deformation while maintaining a flexible feel.

[0008] Furthermore, the degree of polymerization of the PVC resin is 1300-1500. A higher degree of polymerization results in longer molecular chains and more entanglement points, leading to better tensile strength, tear strength, abrasion resistance, and toughness of the material. However, it also leads to severe molecular chain entanglement, high flow resistance in the molten state, very high viscosity, and poor flowability. This creates difficulties in injection molding, extrusion, and other processing methods, requiring higher temperatures and pressures. Considering both product performance and processing performance, the degree of polymerization of the PVC resin is set to 1300-1500.

[0009] Furthermore, the plasticizer is DINP or DOTP.

[0010] DINP stands for diisononyl phthalate; DOTP stands for dioctyl terephthalate.

[0011] Furthermore, the TPU / PVC modified film also includes a pigment component.

[0012] The second aspect of this application provides a method for preparing the TPU / PVC modified film described in the first aspect of this application, comprising the following steps:

[0013] S1: Mix all formulation components except for polyether-type TPU evenly to obtain the first mixture;

[0014] S2: The first mixture and polyether-type TPU are mixed at high temperature for 4-5 minutes using an internal mixer to obtain a second mixture in a molten state;

[0015] S3: Calender and emboss the second mixture to obtain the TPU / PVC modified film.

[0016] Unlike existing technologies, the above technical solution involves mixing PVC and plasticizer, resulting in physical mixing and swelling to obtain plasticized PVC. Through heating in a mixer, both the plasticized PVC and polyether-based TPU are in a molten state. Under high temperature and high shear force, TPU and plasticized PVC undergo a certain degree of interpenetration and entanglement, potentially forming a structure with TPU as the continuous phase and plasticized PVC as the dispersed phase. TPU acts as the "skeleton," providing elasticity and toughness, while plasticized PVC acts as the "filler," providing strength and cost advantages; the two complement each other. TPU provides the material with wear resistance, low-temperature resistance, and elasticity, while PVC provides some reinforcement, thereby reducing the overall price.

[0017] Furthermore, in the calendering step, the temperature of the calendering rollers is 170-180°C.

[0018] A third aspect of this application provides a space composite material, which has a sandwich structure, comprising a top layer and a bottom layer of the TPU / PVC modified film described in the first aspect of this application, and a middle layer of space mesh fabric; the space composite material is obtained by bonding the top layer, the middle layer, and the bottom layer at a high temperature of 165-182℃ and a pressure of 30-40 kg / m². 2 .

[0019] Furthermore, the intermediate layer is coated with PVC paste on both sides and preheated at 170-185°C before bonding, and the top layer and bottom layer are preheated at 148-153°C before bonding.

[0020] Because TPU / PVC modified films have a high TPU content, the preheating temperature must be controlled between 148-153℃ to prevent the TPU / PVC modified films from sticking to the rollers during processing.

[0021] Unlike existing technologies, the above-mentioned spatial composite material combines the advantages of TPU and PVC. It has a light odor, good flexibility, low temperature resistance, weather resistance, and hydrolysis resistance, and is reasonably priced. It can meet the requirements of high-end agricultural greenhouses (high temperature and high humidity conditions) and the inflatable home furnishing market (low odor).

[0022] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the textual description, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is based on the specific embodiments of this application. Detailed Implementation

[0023] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following detailed description is provided in conjunction with specific embodiments.

[0024] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description is provided in conjunction with the specific embodiments listed. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended only as examples, not as limiting the scope of protection of this application.

[0025] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0026] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0027] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0028] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order between these entities or operations.

[0029] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0030] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0031] The first aspect of this application provides a TPU / PVC modified film with a thickness of 0.50-0.65 mm, comprising the following components: 50-75 parts by weight of polyether-type TPU; 25-50 parts by weight of PVC resin; 20-35 parts by weight of plasticizer; 1-2 parts by weight of composite calcium-zinc stabilizer; 0.4-0.6 parts by weight of UV absorber; 0.2-0.5 parts by weight of composite antioxidant; and 0-0.2 parts by weight of lubricant.

[0032] Unlike existing technologies, the above-mentioned technical solution provides a TPU / PVC modified film, which is mainly composed of polyether-type TPU raw materials. The film produced has good flexibility, good low-temperature resistance, and a longer service life due to folding. At the same time, blending with PVC resin not only reduces costs but also effectively improves the material's resistance to yellowing and hydrolysis. The overall formula maintains softness while significantly reducing plasticizers, effectively reducing migration and maintaining the material's good performance. In addition, the formula contains little or no lubricant, which ensures smooth film production and avoids lubricant precipitation during subsequent processing, which is beneficial for high-temperature and adhesive processing.

[0033] Furthermore, the total amount of the polyether-type TPU and PVC resin is 100 parts by weight.

[0034] Furthermore, the polyether-type TPU has a hardness of 70-88A. This hardness level provides the polyether-type TPU with good flexibility, toughness, and mechanical strength. It can provide sufficient "skeleton" support, making the film less prone to deformation while maintaining a flexible feel.

[0035] Furthermore, the degree of polymerization of the PVC resin is 1300-1500. A higher degree of polymerization results in longer molecular chains and more entanglement points, leading to better tensile strength, tear strength, abrasion resistance, and toughness of the material. However, it also leads to severe molecular chain entanglement, high flow resistance in the molten state, very high viscosity, and poor flowability. This creates difficulties in injection molding, extrusion, and other processing methods, requiring higher temperatures and pressures. Considering both product performance and processing performance, the degree of polymerization of the PVC resin is set to 1300-1500.

[0036] Furthermore, the plasticizer is DINP or DOTP.

[0037] DINP stands for diisononyl phthalate; DOTP stands for dioctyl terephthalate.

[0038] Furthermore, the TPU / PVC modified film also includes a pigment component.

[0039] The second aspect of this application provides a method for preparing the TPU / PVC modified film described in the first aspect of this application, comprising the following steps:

[0040] S1: Mix all formulation components except for polyether-type TPU evenly to obtain the first mixture;

[0041] S2: Mix the first mixture with polyether-type TPU using an internal mixer for 4-5 minutes to obtain a second mixture in a molten state;

[0042] S3: Calender and emboss the second mixture to obtain the TPU / PVC modified film.

[0043] Unlike existing technologies, the above technical solution involves mixing PVC and plasticizer, resulting in physical mixing and swelling to obtain plasticized PVC. As the internal mixer heats up, the plasticized PVC and polyether-type TPU are in a molten state. Under high temperature and high shear force, TPU and plasticized PVC undergo a certain degree of interpenetration and entanglement, potentially forming a structure with TPU as the continuous phase and plasticized PVC as the dispersed phase. TPU acts as the "skeleton," providing elasticity and toughness, while plasticized PVC acts as the "filler," providing strength and cost advantages; the two complement each other. TPU provides the material with wear resistance, low-temperature resistance, and elasticity, while PVC provides some reinforcement and reduces the overall price. Because the film is produced using a calendering process, compared to the casting extrusion process, this solution does not require pre-granulation, increasing efficiency by at least 2 times; the mixing effect is better, resulting in a more uniform film thickness, which is more beneficial for inflatable products.

[0044] Furthermore, the mixing temperature is gradually increased until the materials melt and mix. In this technical solution, the mixing temperature reaches 180-190℃.

[0045] Furthermore, in the calendering step, the temperature of the calendering rollers is 170-180°C.

[0046] A third aspect of this application provides a space composite material, which has a sandwich structure, comprising a top layer and a bottom layer of the TPU / PVC modified film described in the first aspect of this application, and a middle layer of space mesh fabric; the space composite material is obtained by bonding the top layer, the middle layer, and the bottom layer at a high temperature of 165-182℃ and a pressure of 30-40 kg / m². 2 .

[0047] Furthermore, the intermediate layer is coated with PVC paste on both sides and preheated at 170-185°C before bonding, and the top layer and bottom layer are preheated at 148-153°C before bonding.

[0048] Unlike existing technologies, the above-mentioned spatial composite material combines the advantages of TPU and PVC. It has a light odor, good flexibility, low temperature resistance, weather resistance, and hydrolysis resistance, and is reasonably priced. It can meet the requirements of high-end agricultural greenhouses (high temperature and high humidity conditions) and the inflatable home furnishing market (low odor).

[0049] In this embodiment, chilled water and air knives work together to control the temperature of the embossing roller below 80°C. The embossing roller temperature is controlled by a cooling water temperature controller, with a settable temperature. The water flows into the high-speed rotating embossing roller through a rotary joint. The return water temperature rises, flowing back to the chiller for re-cooling, forming a closed loop. The air knife is a device that provides high-speed, uniform, sheet-like airflow from an air compressor, exchanging heat with the roller surface and removing a significant amount of heat. Simultaneously, the airflow also blows away any trace moisture or dust that may be present on the roller surface, serving a cleaning function. The temperature sensing device on the embossing roller controls temperature stability by monitoring the temperatures at three points: left, center, and right.

[0050] In this embodiment, the intermediate layer space mesh is ironed and then enters the paste application area. Paste is applied to both surfaces of the mesh, and after drying in an oven, it is laminated at high temperature with a heated film on a large roller. After embossing and cooling, the modified TPU / PVC space composite material is obtained. The ironing temperature of the mesh is 90-110℃, the paste application amount on one side is 70-100 gsm, and the oven temperature is 170-185℃. The heating temperature of the TPU / PVC modified film is 148-153℃, the large roller lamination temperature is 165-182℃, and the lamination pressure is 30-40 kg / m². 2 Embossing pressure is 25-35 kg / m 2 .

[0051] In this embodiment, the hardness of the polyether-type TPU is 85A, the PVC resin is SG2, the plasticizer is DINP, the composite calcium-zinc stabilizer is LF-L1501, the UV absorber is UV-531, the composite antioxidant is 330, and the lubricant is stearic acid.

[0052] Example 1: A TPU / PVC modified film and a TPU / PVC modified space composite material

[0053] S0: Weigh out 50 parts by weight of polyether-type TPU; 50 parts by weight of PVC resin; 35 parts by weight of plasticizer; 2 parts by weight of composite calcium-zinc stabilizer; 0.6 parts by weight of UV absorber; 0.5 parts by weight of composite antioxidant; and 0.2 parts by weight of lubricant.

[0054] S1: PVC resin, plasticizer, composite calcium-zinc stabilizer, UV absorber, composite antioxidant, and lubricant are mixed evenly using a high-speed mixer to obtain the first mixture;

[0055] S2: Mix the first mixture with polyether-type TPU at high temperature for 4-5 minutes using a mixer to obtain a molten second mixture;

[0056] S3: The second mixture is calendered using a five-roll calender at 170-180℃ and embossed using an embossing roller at 100-120℃ to obtain a TPU / PVC modified film with a thickness of 0.6mm.

[0057] S4: The preheated TPU / PVC modified film, the intermediate space mesh, and the TPU / PVC modified film are bonded together at high temperature on a large roller, and then cooled to obtain a sandwich-structured TPU / PVC modified space composite material. The bonding temperature is 165-182℃, and the pressure is 30-40 kg / m. 2 Before lamination, the space mesh is ironed flat at 90-110℃, coated with PVC paste (70-100gsm on one side), and preheated in an oven at 170-185℃. The TPU / PVC modified film is preheated at 148-153℃ before lamination.

[0058] Example 2: A TPU / PVC modified film and a TPU / PVC modified space composite material

[0059] The difference between Example 2 and Example 1 is that the component formulation in step SO is different, specifically: 75 parts by weight of polyether-type TPU; 25 parts by weight of PVC resin; 20 parts by weight of plasticizer; 1 part by weight of composite calcium-zinc stabilizer; 0.4 parts by weight of UV absorber; 0.25 parts by weight of composite antioxidant; and 0.1 parts by weight of lubricant.

[0060] Example 3: A TPU / PVC modified film and a TPU / PVC modified space composite material

[0061] The difference between Example 3 and Example 1 is that the component formulation in step SO is different, specifically: 60 parts by weight of polyether-type TPU; 40 parts by weight of PVC resin; 32 parts by weight of plasticizer; 1.6 parts by weight of composite calcium-zinc stabilizer; 0.6 parts by weight of UV absorber; 0.4 parts by weight of composite antioxidant; and 0.08 parts by weight of lubricant.

[0062] Comparative Example 1: Commercially available TPU polyurethane space composite material

[0063] Comparative Example 2: Commercially available PVC space composite material

[0064] The performance of the TPU / PVC modified space composite materials prepared in Examples 1-3 and Comparative Examples 1 and 2 was tested, and the results are shown in Table 1:

[0065] Table 1 Performance Test Results

[0066]

[0067] 1. The peel strength test method is: ISO 2411

[0068] 2. The flexibility test method is: hand feel assessment.

[0069] 3. The weather resistance testing method is ASTM G154, with a performance retention rate of >88% after 1000 hours of UV aging.

[0070] 4. The water resistance test method is as follows: after hydrolysis at 85℃ / 85%RH for 500 hours, the strength retention rate is >85%.

[0071] 5. The odor detection method is as follows: Take 50g of sample into an odorless sealed glass bottle, place it in an oven at 80℃ for 24 hours, take it out and evaluate the odor level, cool it to room temperature and then re-evaluate the odor level.

[0072] Grade Strength Description and Judgment Criteria

[0073] Level 1: Odorless - Absolutely no odor detected

[0074] Level 2: Detectable odor is faint, barely perceptible, and not offensive.

[0075] Level 3: Distinct odor, but acceptable.

[0076] Level 4: Strong odor. The odor is strong and unpleasant, barely tolerable.

[0077] Level 5 Strong Odor: The odor is extremely strong, unbearable, and unacceptable.

[0078] Level 6 irritating odor: extremely irritating, causing severe discomfort and is unacceptable.

[0079] Standards: VDA 270, GB / T 14624.2-2008 Plastics - Laboratory Light Source Exposure Test Method

[0080] 6. Low-Temperature Bending Resistance: Standard: GB / T 12586, Test Conditions: -20℃ (simulating harsh winter or cold environment conditions). Bending Angle / Number of Bending Cycles: 1000 repeated bends at approximately 180° on a standard bender. Evaluation Precautions: Bending Angle / Number of Bending Cycles: 1000 repeated bends at approximately 180° on a standard bender.

[0081] As can be seen from the test data in Table 1, the TPU / PVC modified spatial composite material combines the advantages of TPU and PVC, with a light odor, good flexibility, low temperature resistance, weather resistance, hydrolysis resistance, and moderate cost, which can meet the requirements of high-end agricultural greenhouses (high temperature and high humidity conditions) and inflatable home furnishing products market (low odor).

[0082] Finally, it should be noted that although the above embodiments have been described in the description of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application, utilize the content described in this application's description to make equivalent structural or procedural substitutions or modifications, or directly or indirectly implement the technical solutions of the above embodiments in other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A TPU / PVC modified film, characterized in that, The TPU / PVC modified film has a thickness of 0.50-0.65 mm and comprises the following components: 50-75 parts by weight of polyether-type TPU; 25-50 parts by weight of PVC resin; 20-35 parts by weight of plasticizer; 1-2 parts by weight of composite calcium-zinc stabilizer; 0.4-0.6 parts by weight of UV absorber; 0.2-0.5 parts by weight of composite antioxidant; and 0-0.2 parts by weight of lubricant.

2. The TPU / PVC modified film according to claim 1, characterized in that, The total amount of the polyether-type TPU and PVC resin is 100 parts by weight.

3. The TPU / PVC modified film according to claim 1, characterized in that, The hardness of the polyether-type TPU is 70-88A.

4. The TPU / PVC modified film according to claim 1, characterized in that, The degree of polymerization of the PVC resin is 1300-1500.

5. The TPU / PVC modified film according to claim 1, characterized in that, The plasticizer is DINP or DOTP.

6. The TPU / PVC modified film according to claim 1, characterized in that, The TPU / PVC modified film also includes a pigment component.

7. The method for preparing the TPU / PVC modified film according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Mix all formulation components except for polyether-type TPU evenly to obtain the first mixture; S2: Mix the first mixture with polyether-type TPU using an internal mixer for 4-5 minutes to obtain a second mixture in a molten state; S3: Calender and emboss the second mixture to obtain the TPU / PVC modified film.

8. The preparation method according to claim 7, characterized in that, In the calendering step, the temperature of the calendering rollers is 170-180℃.

9. A TPU / PVC modified space composite material, characterized in that, The space composite material has a sandwich structure, with the top and bottom layers being the TPU / PVC modified film as described in any one of claims 1-6, and the middle layer being a space mesh fabric; the space composite material is obtained by bonding the top, middle, and bottom layers together at a high temperature of 165-182℃ and a pressure of 30-40 kg / m. 2 .

10. The space composite material according to claim 9, characterized in that, The intermediate layer is coated with PVC paste on both sides and preheated at 170-185℃ before bonding. The top layer and bottom layer are preheated at 148-153℃ before bonding.

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