Thermoplastic decorative building board

Abstract

A thermoplastic decorative building board comprises at least one core layer. The core layer is made of a thermoplastic binder and a mineral filler. The thermoplastic adhesive accounts for 25%-75%, the mineral filler accounts for 25%-75%, and the sum of all the components is 100%. The thermoplastic adhesive is polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol ester, and the thermoplastic adhesive is polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol ester. The coating is prepared from a polyolefin elastomer, thermoplastic polyurethane or a styrene-butadiene-styrene block copolymer, diol modified copolyester, a carbodiimide hydrolysis stabilizer, an ultraviolet stabilizer, an adhesion promoter, an epoxy functionalized chain extender, a fluoropolymer or polymethyl methacrylate and a functional mineral filler. According to the building board, PETG with the molecular weight of 40,000-60,000 g / mol is selected, and 20-35 wt% of mineral filler is added, so that the qualified bending modulus is achieved.

Description

Technical Field

[0001] This invention belongs to the field of sheet technology, specifically a thermoplastic decorative building sheet. Background Technology

[0002] Polyvinyl chloride (PVC) has long been the preferred material for flooring manufacturing due to its cost-effectiveness and functional suitability. However, growing environmental and health concerns are driving the industry towards alternative thermoplastic materials. Globally, regulatory restrictions on PVC use are being gradually introduced, primarily due to its role as a source of phthalates and the potential release of toxic gases during production, use, or incineration. Furthermore, PVC has poor recyclability, making it difficult to meet circular economy goals. With the increasing importance of sustainable development and health awareness in both consumer and industrial sectors, flooring manufacturers are actively seeking phthalate-free, recyclable, and low-environmental-impact alternatives.

[0003] Polypropylene (PP) has become one of the alternatives to PVC, offering advantages such as low cost, high flexural strength, and customizability. However, PP materials present significant processing challenges. At high temperatures, PP melt viscosity is low, tending towards a semi-liquid state, making it difficult to maintain surface smoothness and consistent sheet thickness during extrusion. Furthermore, although PP is generally durable, its impact resistance is inferior to polyethylene terephthalate (PETG), making it more prone to cracking or denting in high-traffic or high-intensity environments.

[0004] In addition to environmental impacts, mechanical locking structures also have some functional defects. For example, rigid locking structures are susceptible to dimensional deviations, manufacturing tolerances, and installation wear, which can weaken the integrity of the interlocking structure. Summary of the Invention

[0005] In view of this, the present invention provides a thermoplastic decorative building panel to solve the above-mentioned technical problems.

[0006] A thermoplastic decorative building panel includes at least one core layer. The core layer is made of a thermoplastic adhesive and mineral fillers. The thermoplastic adhesive comprises 25%-75%, and the mineral fillers comprise 25%-75%, with the total of all components being 100%. The thermoplastic adhesive is made of polyethylene terephthalate-1,4-cyclohexanediol ester, polyolefin elastomer, thermoplastic polyurethane or styrene-butadiene-styrene block copolymer, glycol-modified copolyester, carbodiimide hydrolytic stabilizer, ultraviolet stabilizer, adhesion promoter, epoxy functionalized chain extender, fluoropolymer or polymethyl methacrylate, and functional mineral fillers.

[0007] Further, by weight percentage, the polyethylene terephthalate accounts for 50%–70%, the polyolefin elastomer accounts for 5%–10%, the thermoplastic polyurethane or styrene-butadiene-styrene block copolymer accounts for 5%–10%, the glycol-modified copolyester accounts for 6%–15%, the carbodiimide hydrolytic stabilizer accounts for 0.5%–1%, the ultraviolet stabilizer accounts for 0.5%–2%, the adhesion promoter accounts for 0.1%–1%, the epoxy functionalized chain extender accounts for 0.8%–2%, the fluoropolymer or polymethyl methacrylate accounts for 0.1%–1%, and the functional mineral filler accounts for 20%–35%, with the total of the above components being 100%.

[0008] Furthermore, before mixing the polyethylene terephthalate-1,4-cyclohexanediethanol ester with other components, the polyethylene terephthalate-1,4-cyclohexanediethanol ester is first blended with the polyolefin elastomer, thermoplastic polyurethane, or styrene-butadiene-styrene block copolymer for grafting.

[0009] Furthermore, after blending the polyethylene terephthalate-1,4-cyclohexanediol ester with the polyolefin elastomer, thermoplastic polyurethane, or styrene-butadiene-styrene block copolymer, the mixture of PETG with polyolefin elastomer (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymer (SBS) is copolymerized with glycol-modified copolyester.

[0010] Furthermore, the functional mineral filler is one or any combination of limestone, talc, calcium carbonate, magnesium, magnesium hydroxide, and aluminum hydroxide.

[0011] Furthermore, the molecular weight of the PETG must be in the range of 40,000 to 60,000 g / mol.

[0012] Furthermore, the adhesion promoter is one or a combination of silicon-based, organosilicon-based, titanate-based, zirconate-based, maleic anhydride graft polymer, epoxy functionalized compound, and phosphate ester.

[0013] Furthermore, the core layer is a co-extruded core layer.

[0014] Furthermore, the extruder used in the production of the thermoplastic decorative building panels has an aspect ratio of 34:1.

[0015] Furthermore, the temperature of the feed zone of the extruder is 180°C to 190°C, the temperature of the compression zone is 190°C to 205°C, and the temperature of the die zone is 200°C to 210°C.

[0016] Furthermore, the screw compression ratio of the extruder is ≤2:1.

[0017] Furthermore, the thermoplastic decorative building panel also includes a decorative layer disposed on the front side of the core layer, the decorative layer being a PETG color film layer; a wear-resistant layer disposed on the decorative layer; a back layer disposed on the back side of the core layer, the back layer being a polyethylene (PE) layer; and a mechanical locking structure integrated into the side of the panel.

[0018] Furthermore, the thermoplastic decorative building panel also includes a decorative layer disposed on one side of the core layer, the decorative layer being a PETG color film layer; a wear-resistant layer disposed on the free side of the decorative layer; a back layer disposed on the other side of the core layer, the back layer being a polyethylene (PE) layer; and a mechanical locking structure integrated into the side of the panel.

[0019] Compared with existing technologies, the thermoplastic decorative building panel provided by this invention achieves a qualified flexural modulus by selecting PETG with a molecular weight of 40,000–60,000 g / mol and adding 20–35 wt.% mineral filler. Simultaneously, this specific molecular weight range provides suitable melt viscosity during extrusion, ensuring uniform filler dispersion, which is crucial for the consistency of the overall flexural performance of the core layer. During manufacturing, the PETG is first blended with polyolefin elastomer (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymer (SBS). These polymers impart superior ductility and elongation while maintaining material transparency and processing compatibility. Then, a copolymerization reaction is carried out with glycol-modified copolyester, thereby directly embedding molecular-level flexibility into the polymer backbone. This controls crystallinity and improves molecular chain mobility, ultimately significantly enhancing the molding performance of the finished material. This improves the overall impact resistance of the material, achieving an optimal balance between stiffness and flexibility. This ensures that the flooring board resists bending deformation under load while maintaining sufficient ductility to absorb impact energy without cracking. Furthermore, the addition of carbodiimide hydrolytic stabilizers, UV stabilizers, fluoropolymers, or polymethyl methacrylate (PMMA) gives the prepared board excellent stability and moisture resistance, ensuring long-term moisture resistance. Detailed Implementation

[0020] The following provides a more detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0021] This invention provides a thermoplastic decorative building panel. The thermoplastic decorative building panel includes at least one core layer, at least one decorative layer disposed on one side of the core layer, and at least one back layer disposed on the other side of the core layer.

[0022] The core layer is made of thermoplastic adhesive and mineral filler. The thermoplastic adhesive accounts for 25%-75%, and the mineral filler accounts for 25%-75%, with the total of the above components being 100%. The thermoplastic adhesive is made of polyethylene terephthalate-1,4-cyclohexanediol, polyolefin elastomer (POE), thermoplastic polyurethane (TPU) or styrene-butadiene-styrene block copolymer (SBS), glycol-modified copolyester, carbodiimide hydrolytic stabilizer, ultraviolet stabilizer, adhesion promoter, epoxy functionalized chain extender, fluoropolymer or polymethyl methacrylate (PMMA), and functional mineral filler. By weight percentage, the polyethylene terephthalate-1,4-cyclohexanedimethyl ester accounts for 50% to 70%, the polyolefin elastomer (POE) accounts for 5% to 10%, the thermoplastic polyurethane (TPU) or styrene-butadiene-styrene block copolymer (SBS) accounts for 5% to 10%, the glycol-modified copolyester accounts for 6% to 15%, the carbodiimide hydrolytic stabilizer accounts for 0.5% to 1%, the ultraviolet stabilizer accounts for 0.5% to 2%, the adhesion promoter accounts for 0.1% to 1%, the epoxy functionalized chain extender accounts for 0.8% to 2%, the fluoropolymer or polymethyl methacrylate accounts for 0.1% to 1%, and the functional mineral filler accounts for 20% to 35%, with the total of all the above components being 100%.

[0023] The polyethylene terephthalate-1,4-cyclohexanediethanol ester, officially named polyethylene terephthalate-1,4-cyclohexane dimeth yleneterephthalate, is a transparent, amorphous copolyester. The commonly used comonomer for PETG is 1,4-cyclohexanediethanol (CHDM, Cyclohexylene dimethylene), also known as polyethylene terephthalate-1,4-cyclohexanediethanol ester. It is a product of transesterification polymerization of terephthalic acid (PTA), ethylene glycol (EG), and 1,4-cyclohexanediethanol (CHDM). Compared to PET, it contains the 1,4-cyclohexanediethanol comonomer, and compared to PCT, it contains the ethylene glycol comonomer. Therefore, the properties of PETG are significantly different from those of PET and PCT.

[0024] PETG is a non-crystalline copolyester. During its production process, a certain amount of ethylene glycol is replaced by 1,4-cyclohexane dimethanol (CHDM), which prevents crystallization and thus improves processing and transparency.

[0025] The molecular weight of PETG varies depending on the amount of ethylene glycol replaced by CHDM. In this invention, the molecular weight of PETG must be in the range of 40,000 to 60,000 g / mol. By controlling the molecular weight of PETG, efficient extrusion can be achieved at lower processing temperatures, such as below 200°C. This controlled molecular weight specification ensures high mechanical properties while minimizing the risk of premature crystallization and thermal degradation. When the molecular weight (Mw) of PETG is below 40,000 g / mol, the melt viscosity is too low, which can easily lead to filler sedimentation, resulting in uneven core density and the formation of mechanically weak areas. Conversely, when the molecular weight of PETG exceeds 60,000 g / mol, the melt viscosity is too high, which not only generates excessive shear force during extrusion, affecting filler dispersion, but also triggers thermal degradation, ultimately damaging the mechanical properties of the product. Meanwhile, the PETG content should not exceed 50%–70%. If the PETG content is below 50%, the performance of PETG cannot be fully utilized, resulting in boards with too low strength and poor mechanical properties, making them unsuitable for use as flooring or wall panels. Conversely, if the PETG content is too high, such as above 70%, it will be difficult to extrude, requiring very high temperatures for extrusion.

[0026] When blending with other substances, PETG is first blended with polyolefin elastomer (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymer (SBS). These polymers impart superior ductility and elongation while maintaining material transparency and processing compatibility. The reason for first blending PETG with these substances is to graft them onto the PETG, forming longer chains that improve the overall flexibility of the material, thereby enhancing the polymer's ductility and elongation. Failure to first blend with these substances introduces other materials, which can negatively impact the performance of PETG. The content of the polyolefin elastomer (POE) and thermoplastic polyurethane (TPU) or styrene-butadiene-styrene block copolymer (SBS) should not exceed 5% to 10%. This is because if the content of POE, TPU, and SBS is less than 5%, the PETG cannot be completely grafted and blended, leading to inconsistent uniformity in the resulting sheets and resulting in blocky peeling. Conversely, if the content of POE, TPU, and SBS exceeds 10%, some of the POE, TPU, and SBS will remain. Since POE, TPU, and SBS all have a certain degree of elasticity, this excess material will not only affect the extrusion effect, such as making extrusion difficult due to excessive adhesion, or resulting in uneven extruded sheets.

[0027] Then, the PETG is copolymerized with a mixture of polyolefin elastomer (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymer (SBS) and a glycol-modified copolyester. This allows for the direct implantation of molecular-level flexibility into the polymer backbone, thereby controlling crystallinity and improving molecular chain mobility, ultimately significantly enhancing the molding performance of the finished material and improving its overall impact resistance. The glycol-modified copolyester is produced by esterification and polymerization reactions of raw material components including terephthalic acid, ethylene glycol, neopentyl glycol, catalyst, phosphoric acid stabilizers, and colorants. The proportion of the glycol-modified copolyester should not exceed 6%–15%. If the content of the glycol-modified copolyester is less than 6%, PTEG cannot be completely copolymerized with the glycol-modified copolyester, resulting in uneven quality of the extruded sheet, sometimes making extrusion difficult, and even if extruded, some areas of the sheet cannot withstand high pressure and are easily dented. If the content is greater than 15%, there will be excess glycol-modified copolyester. Since glycol-modified copolyester is an additive that can lower the melting point, the resulting board will not be resistant to high temperatures and will foam.

[0028] The carbodiimide hydrolytic stabilizer reacts with the carboxyl end groups induced by moisture, effectively blocking the hydrolytic chain-severing reaction of the polymer formed by the above-mentioned copolymerization reaction. This is because the compounds copolymerized with PETG and polyolefin elastomers (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymers (SBS), as well as glycol-modified copolyesters, are unstable. Without this hydrolytic stabilizer, the moisture absorbed by the board before and during processing, as well as during use, will lead to dimensional changes, especially warping, which not only affects installation accuracy but also jeopardizes long-term stability. The content of the carbodiimide hydrolytic stabilizer should be limited to 0.5%–1%. If it is below 0.5%, it will not play its due role, i.e., it will not prevent hydrolysis. If it is above 1%, it will be wasteful, as the carbodiimide hydrolytic stabilizer will act as a filler, and its density is very low (0.877 g / mL at 20°C), which will reduce the overall strength of the board.

[0029] The UV stabilizer can be one or a mixture of hindered amine light stabilizers (HALS), benzotriazole UV absorbers, and nano-titanium dioxide (TiO2) / zinc oxide (ZnO). PETG is prone to UV degradation, a process primarily triggered by hydrolysis under UV radiation. This phenomenon manifests as photodegradation, characterized by surface chalking, color changes, and loss of material structural integrity. For applications exposed to sunlight or high-intensity UV environments, unless protective measures are taken, the lifespan and aesthetic durability of PETG will be severely limited. The content of the UV stabilizer is also limited to 0.5%–2%. If it is below 0.5%, it cannot effectively prevent photodegradation, resulting in chalking or color changes on parts of the sheet surface. If it is above 2%, it will lead to material waste.

[0030] The epoxy functionalized chain extender, such as Joncryl ADR 4368, is used to reconnect broken polymer chains to repair molecular weight, thereby restoring the material's mechanical strength and processing stability. During processing, continuous stirring and extrusion processes can cause the long-chain materials formed through copolymerization to break. Therefore, adding the epoxy functionalized chain extender allows the broken polymer chains to reconnect, thus preventing damage to mechanical strength and processing stability. The content of the epoxy functionalized chain extender should be limited to 0.8%–2%. If it is below 0.8%, it will not have the desired effect, while if it is above 2%, the content is too high and wasteful. Furthermore, the epoxy functionalized chain extender can also affect the density of the extruded sheet, such as causing a decrease in sheet density.

[0031] The fluoropolymer or polymethyl methacrylate (PMMA) is used to form a protective layer, creating a highly effective moisture barrier on the surface of the extruded sheet. This protective layer prevents the base polymer from being exposed to high humidity or chemically corrosive environments for extended periods, significantly improving the weather resistance and lifespan of PETG sheets, especially for flooring and construction applications. The content of the fluoropolymer or PMMA should be limited to 0.1% to 1%. Below 0.1%, a complete protective layer cannot be formed, while above 1% would be wasteful. Furthermore, since both fluoropolymers and PMMA are plastics, they are relatively hard and considered hazardous substances, therefore, they are not suitable for large-scale use.

[0032] The functional mineral filler can be calcium carbonate (CaCO3), talc, silicon dioxide (SiO2), etc. The functional mineral filler is used to improve the rigidity of the manufactured board and also reduces costs. The functional mineral filler itself is existing technology and will not be described in detail here. The content of the functional mineral filler is 20%–35%, and it should be added last, so its content usually will not exceed the standard.

[0033] The adhesion promoter can be a silane coupling agent, which is used to improve moisture resistance. The silane coupling agent can enhance the bonding force between the filler and matrix interface, forming a hydrophobic interface to block moisture penetration. Simultaneously, the added carbodiimide hydrolytic stabilizer can neutralize the hydrolytic degradation reaction, thereby ensuring long-term moisture resistance stability. The content of the adhesion promoter should be limited to 0.1% to 1%. If the content of the silane coupling agent is less than 0.1%, a complete interfacial bonding force cannot be formed, and moisture penetration cannot be completely blocked, affecting the subsequent use of the board. If it is greater than 1%, since the main property of the silane coupling agent is adhesiveness, i.e., it has a certain degree of stickiness, this will affect the extrusion of the board, which is detrimental to extrusion.

[0034] In addition, it is conceivable that, in order to meet different needs, pigments can be added to the raw materials used to make the boards to produce boards of different colors.

[0035] The decorative layer can be formed from a patterned film, which may be made of a paper layer and / or a polymer layer, such as a PVC layer or a PETG color film layer. A wear-resistant layer, typically substantially transparent, may also be provided on the decorative layer, i.e., on the side opposite to the core layer. The wear-resistant layer may consist of one or more layers of transparent varnish. The decorative layer itself is prior art and will not be described further here.

[0036] In addition, the side of the building panel is also integrated with a mechanical locking structure, which is used to assemble two adjacent panels together.

[0037] The backing layer, also known as the balancing layer, can be made of polyethylene (PE), giving the building panel waterproof, anti-warping, and anti-bulging functions, preventing surface bending and thus making the product more stable. In summary, by setting the balancing layer, warping and bulging can be reduced or eliminated for existing panels. The protective layer is also existing technology and will not be described further.

[0038] When extruding sheets made from the aforementioned materials, the extrusion system is specifically designed to meet the unique processing requirements and degradation susceptibility of PETG. PETG requires relatively high extrusion temperatures to avoid premature crystallization, but operating temperatures exceeding 200°C may lead to thermal degradation. Furthermore, PETG is highly sensitive to shear degradation, necessitating a low-speed, low-shear extrusion process. Existing extrusion lines, however, are designed for high-speed, high-shear processing, significantly increasing the risk of material degradation.

[0039] To overcome these technical challenges, this extruder employs an optimized length-to-diameter ratio (L / D) of 34:1 or higher, ensuring the extended residence time required for thorough homogenization while preventing induced thermal or shear degradation. The extrusion line integrates a vacuum degassing system, effectively removing moisture and volatiles, significantly reducing the likelihood of hydrolytic degradation during processing.

[0040] The optimized temperature profile for PETG extrusion processes strikes a balance between preventing premature crystallization and avoiding thermal degradation. Feeding zone temperature: 180°C to 190°C; Compression zone temperature: 190°C to 205°C; Die head area temperature: 200°C to 210°C; Screw speed: 20-40 revolutions per minute.

[0041] This temperature profile ensures good material flowability during processing while minimizing the risk of thermal degradation. To control shear sensitivity, this process uses a low-compression screw with a compression ratio ≤2:1 and replaces high-shear kneading elements with distribution mixing elements, effectively limiting shear stress and maintaining the molecular integrity of the polymer matrix. Furthermore, the use of a low molecular weight PETG grade with optimized intrinsic viscosity enables stable extrusion at controlled temperatures, significantly reducing the risk of degradation.

[0042] After extrusion molding, the molten sheet undergoes a three- or five-roll calendering system to ensure uniform thickness and surface smoothness—crucial for subsequent bonding of decorative layers. It is then cooled using water-cooled rollers, and an optimized cooling profile promotes the formation of a semi-crystalline structure within the PETG matrix, significantly reducing the proportion of amorphous regions that are more prone to moisture absorption and hydrolysis. This semi-crystalline morphology effectively enhances the moisture resistance and dimensional stability of the core composite material.

[0043] To address potential degradation issues caused by UV radiation and moisture in non-neutral pH environments after extrusion, this core layer composite material incorporates UV stabilizers and hydrolysis-resistant additives. Silane coupling agents are used to modify surface-treated mineral fillers such as calcium carbonate (CaCO3), silica (SiO2), and talc. These treatment processes enhance the filler-matrix interfacial bonding, eliminate capillary penetration channels, and form a dense, aggregated structure, thereby significantly improving the board's resistance to moisture penetration and UV degradation.

[0044] The extrusion die used can be extended by at least 100 mm on one side, increasing the residence time of the material in the die and enabling gradual pressure reduction, effectively avoiding dimensional instability caused by sudden expansion. This extension design also ensures that the extruded material is demolded at the optimal processing temperature, promoting stable crystallization and maintaining the mechanical integrity of the sheet.

[0045] Compared with existing technologies, the PTEG-based sheet provided by this invention achieves a qualified flexural modulus by selecting PETG with a molecular weight of 40,000–60,000 g / mol and adding 20–35 wt.% mineral filler. Simultaneously, this specific molecular weight range provides suitable melt viscosity during extrusion, ensuring uniform filler dispersion, which is crucial for the consistency of the overall flexural performance of the core layer. During manufacturing, the PETG is first blended with polyolefin elastomer (POE), thermoplastic polyurethane (TPU), or styrene-butadiene-styrene block copolymer (SBS). These polymers impart superior ductility and elongation while maintaining material transparency and processing compatibility. Then, a copolymerization reaction is carried out with glycol-modified copolyester, thereby directly embedding molecular-level flexibility into the polymer backbone. This controls crystallinity and improves molecular chain mobility, ultimately significantly enhancing the molding performance of the finished material. This improves the overall impact resistance of the material, achieving an optimal balance between stiffness and flexibility. This ensures that the flooring board resists bending deformation under load while maintaining sufficient ductility to absorb impact energy without cracking. Furthermore, the addition of carbodiimide hydrolytic stabilizers, UV stabilizers, fluoropolymers, or polymethyl methacrylate (PMMA) gives the prepared board excellent stability and moisture resistance, ensuring long-term moisture resistance.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions or improvements within the spirit of the present invention are covered within the scope of the claims of the present invention.

Claims

1. A thermoplastic decorative building panel, characterized in that: The thermoplastic decorative building board comprises at least one core layer made of a thermoplastic adhesive and a mineral filler, the thermoplastic adhesive accounts for 25%-75%, the mineral filler accounts for 25%-75%, the sum of the above components is 100%, the thermoplastic adhesive is a mixture of polyethylene terephthalate-1, 4-cyclohexane dimethanol, polyolefin elastomer, thermoplastic polyurethane or styrene-butadiene-styrene block copolymer, diol modified copolyester, carbodiimide hydrolysis stabilizer, ultraviolet stabilizer, adhesion promoter, epoxy functional chain extender, fluoropolymer or polymethyl methacrylate.

2. The thermoplastic decorative building panel of claim 1, wherein: After the polyethylene terephthalate-1, 4-cyclohexane dimethanol is blended with the polyolefin elastomer, thermoplastic polyurethane or styrene-butadiene-styrene block copolymer, the mixture of the PETG, polyolefin elastomer (POE), thermoplastic polyurethane (TPU) or styrene-butadiene-styrene block copolymer (SBS) and the diol modified copolyester are subjected to copolymerization reaction.

3. The thermoplastic decorative building panel of claim 2, wherein: After the polyethylene terephthalate-1, 4-cyclohexane dimethanol is blended with the polyolefin elastomer, thermoplastic polyurethane or styrene-butadiene-styrene block copolymer, the mixture of the PETG, polyolefin elastomer (POE), thermoplastic polyurethane (TPU) or styrene-butadiene-styrene block copolymer (SBS) and the diol modified copolyester are subjected to copolymerization reaction.

4. The thermoplastic decorative building panel of claim 1, wherein: The polyethylene terephthalate accounts for 50%-70%, the polyolefin elastomer accounts for 5%-10%, the thermoplastic polyurethane or styrene-butadiene-styrene block copolymer accounts for 5%-10%, the diol modified copolyester accounts for 6%-15%, the carbodiimide hydrolysis stabilizer accounts for 0.5%-1%, the ultraviolet stabilizer accounts for 0.5%-2%, the adhesion promoter accounts for 0.1%-1%, the epoxy functional chain extender accounts for 0.8%-2%, and the fluoropolymer or polymethyl methacrylate accounts for 0.1%-1%.

5. The thermoplastic decorative building panel of claim 1, wherein: The mineral filler is one or any combination of limestone, talcum powder, calcium carbonate, magnesium, magnesium hydroxide and aluminum hydroxide.

6. The thermoplastic decorative building panel of claim 1, wherein: The molecular weight of the polyethylene terephthalate ranges from 40,000 to 60,000 g / mol.

7. The thermoplastic decorative building panel of claim 1, wherein: The adhesion promoter is one or a combination of silicon-based, organosilicon-based, titanate-based, zirconate-based, maleic anhydride grafted polymer, epoxy functional compound and phosphate ester.

8. The thermoplastic decorative building panel of claim 1, wherein: The core layer is a co-extrusion core layer.

9. The thermoplastic decorative building panel of claim 1, wherein: The thermoplastic decorative building board is extruded by an extruder, the feeding zone temperature of the extruder is 180-190℃, the compression zone temperature is 190-205℃, and the die zone temperature is 200-210℃.

10. The thermoplastic decorative building panel of claim 8, wherein: The screw compression ratio of the extruder is ≤2:

1.

11. The thermoplastic decorative building panel of claim 1, wherein Further comprising: The thermoplastic decorative building board further comprises a decorative layer arranged on one side of the core layer, the decorative layer is a PETG color film layer; a wear-resistant layer arranged on the free side of the decorative layer; a back layer arranged on the other side of the core layer, the back layer is a polyethylene (PE) layer; and a mechanical lock structure integrated on the side edge of the board.