Flexible polyurethane panel with integrated polyvinyl chloride skin and preparation method thereof

Abstract

The invention relates to a flexible polyurethane panel with an integrated polyvinyl chloride skin, which comprises a panel main body, the panel main body comprises a polyurethane body and a polyvinyl chloride skin, the polyurethane body is formed by reaction of polyether polyol and isocyanate according to a weight ratio of 40: 60-60: 40, and the density of the polyurethane body is 100-400kg / m < 3 >; the thickness of the polyvinyl chloride skin is 0.05-0.30 mm, and the polyvinyl chloride skin and the polyurethane body are integrally formed and seamlessly bonded; comprising the following steps of heating, film laying, mixing and curing. According to the invention, the polyvinyl chloride film is used as the skin, and the closed-pore structure of the polyurethane body is combined, so that the waterproof rate of the panel is greater than or equal to 95%, and the water seepage phenomenon is avoided after 24-72 hours of water soaking test, thereby effectively solving the problem of water seepage of the wall surface; meanwhile, the product is made of fully synthetic materials and does not contain nutritional ingredients needed by termites and moths, insect repellents can be selectively added, the 100% termite-resistant and moth-resistant effects are achieved, and the service life of the material in a humid and insect-rich environment is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of composite material manufacturing technology, and in particular to a flexible polyurethane panel with an integrated polyvinyl chloride skin and its preparation method. Background Technology

[0002] In the field of architectural interior and exterior design and decoration, the performance and applicability of wall, ceiling, and partition materials directly affect the decoration effect, user experience, and maintenance costs. Traditional decoration materials such as wood, gypsum board, and ordinary rigid plastic boards have long suffered from numerous technical defects. Poor adaptability: Traditional materials lack flexibility and cannot fit curved or irregular building structures, which limits designers' creative use of space, especially in scenarios such as arched doorways and curved walls. Vulnerable to damage: Wood materials are easily attacked by termites and woodworms, while gypsum board and ordinary plastic board are prone to mold and water seepage in humid environments, which leads to a shortened lifespan of the materials and an increase in maintenance costs; Cumbersome installation: Traditional materials often rely on plywood, keel and other base materials for fixing, which not only increases material costs, but also leads to complicated and time-consuming installation procedures and high labor costs. Limited performance: Most traditional materials cannot simultaneously meet multiple requirements such as waterproofing, termite prevention, lightweight, and ease of processing, requiring additional protective layers or auxiliary structures, which further increases the complexity and cost of decoration.

[0003] To address these issues, the industry has gradually developed polyurethane-based composite materials. Polyurethane is lightweight, durable, and moldable, and various shapes can be produced through reaction injection molding. However, existing polyurethane-related technologies still have significant shortcomings: some technologies focus only on molding the polyurethane itself, failing to integrate surface finishing with the molding process, resulting in insufficient surface properties (such as waterproofing and scratch resistance); some technologies attempt to integrate surface films, but do not clearly define key process parameters (such as the ratio of polyol to isocyanate, settling time, and drying conditions), and do not use polyvinyl chloride as the skin material, failing to balance flexibility and protection; other technologies employ complex processes such as multi-cavity molds and back injection, leading to low production efficiency, high costs, and products that are difficult to adapt to large panel or curved surface applications.

[0004] Therefore, research on decorative panels applicable to the field of building interior and exterior decoration, especially those suitable for curved spaces and waterproof and termite-proof scenarios, has universal significance. Summary of the Invention

[0005] This invention provides a flexible polyurethane panel with an integrated polyvinyl chloride skin and a method for preparing the same, in order to solve the aforementioned problems of existing decorative panels.

[0006] The present invention adopts the following technical solution: A flexible polyurethane panel with an integrated polyvinyl chloride (PVC) skin includes a panel body comprising a polyurethane matrix and a PVC skin. The polyurethane matrix is ​​formed by reacting polyether polyol and isocyanate in a weight ratio of 40:60 to 60:40, and has a density of 100 to 400 kg / m³. 3 The thickness of the polyvinyl chloride skin is 0.05 to 0.30 mm, and the polyvinyl chloride skin is integrally molded and seamlessly bonded to the polyurethane body.

[0007] Furthermore, the surface of the aforementioned panel is either smooth or textured. The texture is formed by die etching, embossing, or adding color masterbatch to a polyurethane mixture, which can simulate wood grain, stone, or fabric patterns.

[0008] Furthermore, the thickness of the aforementioned panel body is 3 to 30 mm, and the bending radius can reach 25 to 500 mm.

[0009] Furthermore, the dimensions of the main panel body are 300mm×300mm to 3000mm×3000mm.

[0010] A method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin includes the following steps: 1) Heat the concave-convex injection mold to 30-80℃; 2) Lay a thin polyvinyl chloride film with a thickness of 0.05 to 0.30 mm at the bottom of the above mold. The film is used to form the surface finish of the panel. 3) Mix polyether polyol and isocyanate at a weight ratio of 40:60 to 60:40. Functional additives may be selectively added during the mixing process. 4) Under a pressure of 50–200 bar, inject the mixture obtained in step 3) into a mold covered with a polyvinyl chloride film; 5) After injection, allow the mixture to stand in the mold for 5-20 minutes for initial curing and stabilization; 6) Take out the molded panel after step 5) and dry it in an environment with a temperature of 20-40℃ and a humidity of 40%-60% for 12-48 hours to obtain the finished panel.

[0011] Furthermore, the molecular weight of the above-mentioned polyether polyol is 2000-8000, and the hydroxyl value is 20-80 mg KOH / g.

[0012] Furthermore, the aforementioned isocyanate is toluene diisocyanate or methylene diphenyl diisocyanate, and its NCO content is 25% to 35%.

[0013] Furthermore, the functional additives in step (3) are selected from one or more of pigments, flame retardants, UV stabilizers, antibacterial agents, foaming agents, or fillers.

[0014] Furthermore, the foaming agent is added at a rate of 0.5% to 5% of the total mass of the mixture, the flame retardant is added at a rate of 5% to 15%, and the antibacterial agent is added at a rate of 0.1% to 1%.

[0015] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following advantages: 1. This invention uses a polyvinyl chloride film as the outer skin, combined with the closed-cell structure of the polyurethane body, to achieve a panel waterproof rate of ≥95%. After 24-72 hours of water immersion testing, there is no water seepage, effectively solving the problem of wall seepage. At the same time, the product uses fully synthetic materials, does not contain the nutrients needed by termites and woodworms, and can selectively add insect repellents to achieve 100% anti-termite and anti-woodworm effects. After 3-12 months of insect exposure testing, there is no damage, significantly extending the service life of the material in humid and insect-prone environments.

[0016] 2. By precisely controlling the ratio of polyether polyol to isocyanate (40:60 to 60:40) and the thickness of polyvinyl chloride film (0.05 to 0.30 mm), the panel can be bent 360 degrees with a minimum bending radius as low as 25 mm. It can perfectly fit irregular architectural structures such as arched doorways and curved walls, breaking through the shape limitations of traditional materials and greatly improving the flexibility and creativity of space design.

[0017] 3. The product of this invention does not rely on plywood, keel or other base materials and can be directly installed on the wall. The weight per square meter is only 2 to 6 kg, and 1 to 2 people can complete the handling and installation. Compared with traditional materials, the installation time is shortened by 50% and the labor cost is reduced by 30% to 50%. At the same time, the omission of base materials reduces material costs by 15% to 40%, and the material utilization rate in the production process exceeds 95%, further reducing the overall cost.

[0018] 4. This invention uses a single-plate concave-convex mold, eliminating the need for complex multi-cavity structures or back-injection processes, simplifying the production process and reducing the defect rate by 50%. The process parameters (temperature, pressure, ratio, settling and drying time) are clearly defined and can be adjusted according to requirements, enabling diverse customization of product hardness, flexibility, color, and texture. By adding color masterbatch, a variety of colors, from neutral white to bright red, can be obtained. Through mold etching or embossing, textures such as wood grain and stone can be simulated. The size can be flexibly adjusted within the range of 300mm×300mm to 3000mm×3000mm, adapting to various indoor and outdoor application scenarios such as residential, commercial buildings, and furniture.

[0019] 5. This invention uses a reactive system, which has a lower content of volatile organic compounds (VOCs) and is more environmentally friendly compared with solvent-based alternatives. The product can be recycled into low-grade products through grinding and reprocessing, and has certain recycling potential. The production process uses closed molds and automated mixing equipment, and operators can avoid safety risks by wearing protective equipment in accordance with regulations, resulting in high process safety.

[0020] 6. By adding different functional additives during the mixing stage, the panel can have extended functions such as flame retardancy, UV resistance, and antibacterial properties. After adding flame retardants, it can meet the UL94 V-0 flame retardant standard, making it suitable for fire-prone areas; after adding UV stabilizers, it can pass the 1000-hour xenon arc test, making it suitable for outdoor exposure environments; after adding antibacterial agents, it can meet the usage requirements of hospitals and other sanitary places, further expanding the application boundaries of the product. Detailed Implementation

[0021] The present invention will now be described in detail, including its process steps, materials, advantages, variations, embodiments, and product implementation schemes. The process begins with the preparation of complex convex and concave injection molds; four designs have been completed so far, with more under development. These molds are flat and can produce panels of various sizes suitable for wall and ceiling applications, ranging from small decorative pieces (300 mm × 300 mm) to large structural panels (3000 mm × 1500 mm).

[0022] Heating the mold to 30 to 80 degrees Celsius promotes reaction and adhesion while preventing premature curing or film degradation. A thin PVC film, 0.05 to 0.30 mm thick, is placed at the bottom of the mold to provide a smooth surface finish and enhance water resistance, scratch resistance, and aesthetics. This film serves as the outer skin of the panel, enabling seamless integration during molding; various grades of PVC film (including flexible, semi-rigid, or printed PVC) are available to suit different applications.

[0023] Component A (polyether polyol, preferably with a molecular weight of 2000 to 8000 and a hydroxyl value of 20 to 80 mg potassium hydroxide / g) and component B (isocyanate, such as toluene diisocyanate or methylene diphenyl diisocyanate) are mixed at a weight ratio of 40:60 to 60:40. This wide ratio range allows for adjustment of the flexibility and stiffness of the polyurethane: a lower polyol content results in a stiffer panel suitable for outdoor use; a higher polyol content provides excellent flexibility suitable for indoor use. The mixture is injected into a mold under a pressure of 50 to 200 bar, covering the mold cavity with a PVC film to ensure uniform filling without voids.

[0024] After injection, allow the mixture to stand for 5 to 20 minutes to allow for initial curing and stabilization, preventing defects such as bubbles, uneven density, or film delamination. The standing time can be adjusted according to environmental conditions: shorter in warm environments and longer in cold environments to optimize reaction kinetics. After standing, remove the molded panel and dry it in a controlled environment (40% to 60% humidity, 20 to 40 degrees Celsius) for 12 to 48 hours to ensure complete curing, increased strength, and dimensional stability, while preventing cracking or warping.

[0025] The resulting panels possess the following key characteristics: a water resistance of at least 95% after 24 to 72 hours of immersion testing (thanks to the closed-cell structure of polyurethane and the impermeable barrier effect of the PVC skin); direct wall application technology eliminates the need for plywood or plaster substrates, reducing material costs by 15% to 40% and labor costs by 30% to 50%; 100% resistant to termites and woodworms (synthetic components do not contain nutrients needed by pests, and optional insect repellents can be added); 360-degree bending capability with a minimum bending radius ranging from 25 to 500 mm depending on thickness; lightweight (density 100 to 400 kg / m³), facilitating handling and installation by 1 to 2 people; fast installation speed, halving on-site construction time compared to traditional materials; and the ability to be directly painted with standard acrylic or oil-based paints, enabling customization of various colors and finishes.

[0026] Variations of this process include: adjusting the PVC film thickness from 0.05 to 0.30 mm to optimize the surface finish (thinner films achieve maximum flexibility, while thicker films enhance durability); modifying mold designs to produce panels of different shapes (such as rectangles for flat walls, curved surfaces for arches with radii from 25 to 500 mm, or irregular shapes for custom designs); adding pigments, dyes, or masterbatches to the polyurethane blend or film to produce colored panels ranging from neutral white to vibrant red; and achieving textures through mold etching or embossing to mimic wood grain, stone, or fabric patterns. Furthermore, flame retardants, UV stabilizers, or antimicrobial agents can be added to polyols or isocyanates to expand product applications to fire-prone areas, outdoor exposure environments, or sanitary facilities.

[0027] By adjusting the mold size, small residential panels (600 mm × 1200 mm for home décor) or large commercial panels (such as 2400 mm × 1200 mm for office partitions) can be produced. Injection speeds can be varied between 50 and 300 g / s to accommodate different viscosities; a release agent can be applied for easy demolding. For foamed variants, 0.5% to 5% of a foaming agent (such as water or hydrocarbons) can be added to further reduce density while maintaining strength.

[0028] Example 1: A flexible polyurethane panel with an integrated polyvinyl chloride skin includes a panel body, which comprises a polyurethane matrix and a polyvinyl chloride skin. The polyurethane matrix is ​​formed by reacting polyether polyol and isocyanate in a weight ratio of 40:60, and has a density of 100 kg / m³. 3 The thickness of the polyvinyl chloride skin is 0.05 mm, and the polyvinyl chloride skin is integrally molded and seamlessly bonded to the polyurethane body.

[0029] Furthermore, the surface of the aforementioned panel is either smooth or textured. The texture is formed by die etching, embossing, or adding color masterbatch to a polyurethane mixture, which can simulate wood grain, stone, or fabric patterns.

[0030] The thickness of the panel body is 3mm, and the bending radius can reach 300mm.

[0031] The dimensions of the main panel are 2400mm × 600mm.

[0032] A method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin includes the following steps: 1) Heat the concave-convex injection mold to 60℃; 2) Lay a thin polyvinyl chloride film with a thickness of 0.05 mm at the bottom of the above mold. The film is used to form the surface finish of the panel. 3) Mix polyether polyol and isocyanate at a weight ratio of 40:60. Functional additives may be selectively added during the mixing process. 4) Under a pressure of 50–200 bar, inject the mixture obtained in step 3) into a mold covered with a polyvinyl chloride film; 5) After injection, allow the mixture to stand in the mold for 5 minutes for initial curing and stabilization; 6) Take out the molded panel after step 5) and dry it for 20 hours in an environment with a temperature of 30℃ and a humidity of 40% to obtain the finished panel.

[0033] The molecular weight of the above polyether polyol is 6000, and the hydroxyl value is 60 mg KOH / g.

[0034] The above-mentioned isocyanate is toluene diisocyanate or methylene diphenyl diisocyanate, and its NCO content is 25%.

[0035] The functional additives in step (3) are selected from one or more of pigments, flame retardants, UV stabilizers, antibacterial agents, foaming agents or fillers, preferably selected from pigments, flame retardants, UV stabilizers or antibacterial agents.

[0036] The foaming agent is added at 0.5% of the total mass of the mixture, the flame retardant is added at 5%, and the antibacterial agent is added at 0.1%.

[0037] Example 2: A flexible polyurethane panel with an integrated polyvinyl chloride (PVC) skin includes a panel body comprising a polyurethane matrix and a PVC skin. The polyurethane matrix is ​​formed by reacting polyether polyol and isocyanate in a weight ratio of 60:40, and has a density of 400 kg / m³. 3 The thickness of the polyvinyl chloride skin is 0.30 mm, and the polyvinyl chloride skin is integrally molded and seamlessly bonded to the polyurethane body.

[0038] The surface of the aforementioned panel is either smooth or textured. The texture is formed by die etching, embossing, or adding color masterbatch to a polyurethane mixture, which can simulate wood grain, stone, or fabric patterns.

[0039] The thickness of the panel body is 30mm, and the bending radius can reach 500mm.

[0040] The dimensions of the main panel are 2400mm × 600mm.

[0041] A method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin includes the following steps: 1) Heat the concave-convex injection mold to 80℃; 2) Lay a thin polyvinyl chloride film with a thickness of 0.30 mm at the bottom of the above mold. The film is used to form the surface finish of the panel. 3) Mix polyether polyol and isocyanate at a weight ratio of 60:40. Functional additives may be selectively added during the mixing process. 4) Under a pressure of 200 bar, inject the mixture obtained in step 3) into a mold covered with a polyvinyl chloride film; 5) After injection, allow the mixture to stand in the mold for 20 minutes for initial curing and stabilization; 6) Take out the molded panel after step 5) and dry it in an environment of 40°C and 60% humidity for 48 hours to obtain the finished panel.

[0042] The molecular weight of the above polyether polyol is 8000, and the hydroxyl value is 80 mg KOH / g.

[0043] The above-mentioned isocyanate is toluene diisocyanate or methylene diphenyl diisocyanate, and its NCO content is 35%.

[0044] The functional additives in step 3) are selected from one or more of pigments, flame retardants, UV stabilizers, antibacterial agents, foaming agents or fillers, with the preferred functional additives being selected from pigments, flame retardants or UV stabilizers.

[0045] The foaming agent is added at 5% of the total mass of the mixture, the flame retardant is added at 15%, and the antibacterial agent is added at 1%.

[0046] The flexible polyurethane panel of this embodiment underwent experimental testing, as detailed below:

[0047] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A flexible polyurethane panel with an integrated polyvinyl chloride skin, comprising a panel body, characterized in that: The panel body comprises a polyurethane matrix and a polyvinyl chloride (PVC) skin. The polyurethane matrix is ​​formed by reacting polyether polyol and isocyanate in a weight ratio of 40:60 to 60:40, and has a density of 100 to 400 kg / m³. 3 The polyvinyl chloride (PVC) skin has a thickness of 0.05–0.30 mm, and the PVC skin is integrally molded and seamlessly bonded to the polyurethane body.

2. The flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 1, characterized in that: The surface of the panel is either smooth or textured. The texture is formed by die etching, embossing, or adding color masterbatch to a polyurethane mixture, and can simulate wood grain, stone, or fabric patterns.

3. A flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 1, characterized in that: The thickness of the panel body is 3-30mm, and the bending radius can reach 25-500mm.

4. A flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 1, characterized in that: The dimensions of the main panel body are 300mm×300mm to 3000mm×3000mm.

5. The method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 1, characterized in that, Includes the following steps: 1) Heat the concave-convex injection mold to 30-80℃; 2) Lay a layer of thickness at the bottom of the mold. A thin polyvinyl chloride film of 0.05 to 0.30 mm, said film being used to form a surface finish for a panel; 3) Mix polyether polyol and isocyanate at a weight ratio of 40:60 to 60:

40. Functional additives may be selectively added during the mixing process. 4) Under a pressure of 50 to 200 bar, inject the mixture obtained in step (3) into a mold covered with a polyvinyl chloride film; 5) After injection, allow the mixture to stand in the mold for 5-20 minutes for initial curing and stabilization; 6) Take out the molded panel after step 5) and dry it in an environment with a temperature of 20-40℃ and a humidity of 40%-60% for 12-48 hours to obtain the finished panel.

6. The method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 5, characterized in that: The polyether polyol has a molecular weight of 2000-8000 and a hydroxyl value of 20-80 mg KOH / g.

7. The method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 5, characterized in that: The isocyanate is toluene diisocyanate or methylene diphenyl diisocyanate, and its NCO content is 25% to 35%.

8. The method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 5, characterized in that: The functional additives in step (3) are selected from one or more of pigments, flame retardants, UV stabilizers, antibacterial agents, foaming agents or fillers.

9. The method for preparing a flexible polyurethane panel with an integrated polyvinyl chloride skin as described in claim 8, characterized in that: The foaming agent is added at a rate of 0.5% to 5% of the total mass of the mixture, the flame retardant is added at a rate of 5% to 15%, and the antibacterial agent is added at a rate of 0.1% to 1%.

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