Low-warping anti-deformation floor and application

Abstract

The invention relates to the technical field of floors, in particular to a low-warping anti-deformation floor and application. The floor sequentially comprises an upper wear-resistant layer, a color film, a base material layer and a lower wear-resistant layer from top to bottom. Wherein the base material layer is prepared from the following raw materials: copolymerized PP resin, LLDPE resin, a compatilizer, a flexibilizer, inorganic powder, a lubricant, a coupling agent, an antioxidant and a nucleating agent. The raw materials are subjected to hot mixing by a high-speed stirrer and cold mixing by a low-speed stirrer, then are extruded by double screws and then are subjected to thickness adjustment. The multi-layer floor prepared from the base material layer has the advantages of being good in size stability, good in low-temperature performance, simple in process and the like.

Description

Technical Field

[0001] The invention relates to the technical field of flooring, in particular to a low-warping and deformation-resistant flooring and its application. Technical Background

[0002] PVC floor is a lightweight floor decoration material, which refers to the floor produced by polyvinyl chloride materials. Specifically, it refers to the production of polyvinyl chloride and its copolymer resin as the main raw materials, with fillers, plasticizers, stabilizers, colorants and other auxiliary ingredients added. Since the subsequent treatment of polyvinyl chloride materials is inconvenient and does not conform to the concept of environmental protection and sustainable development. Therefore, the production and research and development of polypropylene (PP) flooring has become one of the main research directions. As one of the general plastics, PP resin has excellent mechanical properties, including tensile strength, compressive strength and hardness, outstanding rigidity and bending fatigue resistance, and good chemical stability, water resistance and electrical insulation. It is widely used in different fields.

[0003] However, PP has poor cold resistance and is prone to brittleness at low temperatures, resulting in a decrease in impact resistance. In addition, PP flooring also has problems such as poor shrinkage rate and poor bonding strength between the substrate and the composite film. Summary of the invention

[0004] In view of the above problems, the present invention aims to provide a low-warping and anti-deformation floor to overcome the problems of poor warping shrinkage and poor low-temperature performance of traditional PP floors. In order to solve the above technical problems, the following technical solutions are adopted:

[0005] Firstly, the present invention provides a low-warping and deformation-resistant floor, which comprises, from top to bottom, an upper wear-resistant layer, a color film layer, a substrate layer and a lower wear-resistant layer, wherein the substrate layer is made of the following raw materials in parts by weight: 50 to 100 parts of copolymer PP resin, 10 to 50 parts of LLDPE resin, 2 to 10 parts of compatibilizer, 10 to 20 parts of toughening agent, 50 to 300 parts of inorganic powder, 1 to 3 parts of lubricant, 1 to 5 parts of coupling agent, 0.5 to 2 parts of antioxidant and 0.1 to 1 part of nucleating agent.

[0006] Preferably, the copolymer PP resin is selected from at least one of a homopolymer PP resin, an isotactic copolymer PP resin, and a block copolymer PP resin.

[0007] Preferably, the compatibilizer is selected from at least one of polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, hydrogenated styrene-butadiene-styrene block copolymer grafted with maleic anhydride, and maleic anhydride grafted with ethylene-octene copolymer.

[0008] Preferably, the toughening agent is selected from at least one of a block copolymer of styrene and butadiene, a hydrogenated styrene-butadiene block copolymer, ethylene propylene diene monomer rubber, and a polyolefin elastomer.

[0009] Preferably, the inorganic powder is selected from at least one of calcium carbonate, hydrotalcite, talc powder and mica powder.

[0010] Preferably, the particle size of the inorganic powder is 10 μm to 50 μm.

[0011] Preferably, the lubricant is selected from at least one of PE wax, montan wax, montan wax, calcium stearate, EBS, oleamide and zinc stearate.

[0012] Preferably, the coupling agent is selected from at least one of an aluminate coupling agent, a titanate coupling agent, and a silane coupling agent.

[0013] Preferably, the antioxidant is selected from at least one of hindered phenol antioxidants, aromatic amine antioxidants, phosphite antioxidants, and sulfur-containing ester antioxidants.

[0014] Preferably, the nucleating agent is selected from at least one of fatty carboxylic acid metal compounds, sorbitol benzyl derivatives, aromatic carboxylic acid metal compounds, organic phosphates, and sodium benzoate.

[0015] Preferably, the method for preparing the substrate layer comprises the following steps:

[0016] S1: taking the raw materials of the substrate layer, putting them into a high-speed mixer for hot mixing, and then switching to a low-speed mixer for stirring and cooling to perform cold mixing; obtaining a premix of the substrate layer;

[0017] S2: The substrate layer premix obtained in step S1 is put into a twin-screw extruder, plasticized and then extruded, and then moved to a thickness-fixing roller to adjust the substrate thickness to obtain a substrate layer.

[0018] Preferably, in step S1, the hot mix temperature of the high-speed mixer is 110°C to 180°C, the stirring speed is 300r / min to 400r / min, and the stirring time is 10min to 30min; the cold mix temperature of the low-speed mixer is 40°C to 60°C, the stirring speed is 100r / min to 200r / min, and the stirring time is 3min to 8min.

[0019] Preferably, in step S2, the twin-screw extruder has six functional sections, which are the first zone feeding section, which can continuously feed; the second zone melting section, which can heat the material as a whole to form a molten state; the third zone plasticizing section, which plasticizes the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material; the fourth zone exhaust section, which can discharge the excess pores in the melt; the fifth zone mixing section, which fully mixes the raw materials; the sixth zone extrusion section, which is provided with a die, and the material inside the twin-screw extruder is extruded to form a floor base shape. The temperatures of the screw twin-screw zones are set to 190-120°C for zone 1, 195-190°C for zone 2, 190-180°C for zone 3, 185-175°C for zone 4, 180-170°C for zone 5, and 170-160°C for zone 6. Other settings of the twin-screw extruder include: the confluence core temperature is 180°C and the pressure is 0.1MPa. The main machine speed is 19.6r / min, the current is 220A; the feeding speed is 21r / min, the current is 0.2A; the die temperature is 220°C, and the extrusion width is 1050mm-1350mm; the temperature of the upper and lower rollers of the thickness setting roller in step S2 is 255°C.

[0020] Preferably, the method for preparing the floor comprises the following steps:

[0021] S3: sequentially coating the base material layer with a color film layer and an upper wear-resistant layer, and coating the lower wear-resistant layer; embossing with an embossing roller to form a semi-finished flooring product;

[0022] S4: After the semi-finished floor is coated and tempered, it is punched, sliced, and trimmed to prepare the finished floor.

[0023] Preferably, in step S3, the temperatures of the upper and lower rollers of the film attaching roller are 235°C and 230°C respectively; the temperature of the upper and lower rollers of the bottom film coating roller is 225°C.

[0024] Preferably, in step S4, the coating weight of the semi-finished product is 15 grams, and water bath tempering is adopted, the tempering temperature is 35° C., and the curing is carried out for 24 hours.

[0025] Secondly, the present invention provides the use of the aforementioned low-warping and deformation-resistant floor in the preparation of floor.

[0026] The floor substrate and floor of the present invention have the following beneficial effects:

[0027] (1) The floor substrate is made of a blend of copolymer PP resin and LLDPE resin, supplemented with toughening agents and nucleating agents to improve the shrinkage problem during the PP resin processing process and to increase the bonding strength between the substrate and the color film and wear-resistant layer.

[0028] (2) The floor produced by the method of the present invention reduces the hot pressing step, has a simple process, can save labor, and the produced floor has the advantages of small warping and shrinkage, good low-temperature performance, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the floor of the present invention;

[0030] In the figure, 1 is the upper wear-resistant layer, 2 is the color film layer, 3 is the base material layer, and 4 is the lower wear-resistant layer. DETAILED DESCRIPTION

[0031] Combine the following Figure 1 The present invention is described in detail with reference to the following specific embodiments. It is obvious that the terms about directions in the following embodiments, such as "up", "down", "left", "right", etc., are based on Figure 1 The orientation shown is or is the orientation when the floor is laid, and does not represent the orientation when the product is placed.

[0032] Depend on Figure 1 It can be seen that the floor of the present invention includes an upper wear-resistant layer, a color film layer, a substrate layer, and a lower wear-resistant layer from top to bottom. For the sake of clarity in the description of the specific embodiments, the thickness of the substrate layer in the following embodiments of the present invention is 4 mm, the thickness of the upper wear-resistant layer and the lower wear-resistant layer is 0.2 mm, and the thickness of the color film layer is 0.2 mm. The thickness of each layer is related to the needs of the user and is not a technical feature that affects the effect of the present invention. Therefore, it is only used to demonstrate the specific embodiments and is not regarded as a limitation on the scope of protection. The thickness of each layer of the comparative floor is the same.

[0033] The color film layer is mainly used to color the floor. The color film layer is divided into conventional color film and online color film. The online color film is a color film with black marks. The floor color film layer uses color film as the base material. Through the laminating technology, the color film is covered on the specific layer of the floor to achieve the purpose of decorating the floor. In addition, the color film layer also has the function of moisture-proof. The floor color film can be made of materials such as polyvinyl alcohol, polyester, matte coating agent, PVC, etc.

[0034] The wear-resistant layer is mainly used to protect the color film and the base material layer from wear and corrosion after long-term use. The wear-resistant layer is divided into a smooth surface and an embossed surface. The thickness of different wear-resistant layers can be different, and different oils can be used. The wear-resistant layer can be made of materials such as melamine resin and aluminum oxide and polypropylene resin (PP resin).

[0035] The color film layer and the wear-resistant layer are both conventional industrial products. In the production stage of the floor, the finished products on the market can be used directly without special processing. For the sake of clarity in the description of the specific embodiments, the color film layer in the embodiment of the present invention adopts a line-pair flower color film, and the color film material is purchased from Taichang Color Art Industrial Co., Ltd. (the material is PVC material). The upper wear-resistant layer and the lower wear-resistant layer in the embodiment of the present invention are purchased from Jiangsu Huaxin New Materials Co., Ltd. (the material is PETG, i.e. polyethylene terephthalate-1,4-cyclohexane dimethanol ester material). Since the color film layer and the wear-resistant layer are only used to perform their conventional functions in the present invention, other commercially available color film layers and wear-resistant layers can also be used. Therefore, the color film layer and the wear-resistant layer in the embodiment are only used to demonstrate the specific embodiments, and are not regarded as limiting the scope of protection.

[0036] In the following embodiments, the ingredients of the base material layer of the floor are calculated by weight as follows: 50-100 parts of copolymer PP resin (i.e., copolymer polypropylene resin), 10-50 parts of LLDPE resin (i.e., linear low-density polyethylene resin), 2-10 parts of compatibilizer, 10-20 parts of toughening agent, 50-300 parts of inorganic powder, 1-3 parts of lubricant, 1-5 parts of coupling agent, 0.5-2 parts of antioxidant, and 0.1-1 parts of nucleating agent.

[0037] The copolymer PP resin is a resin material, which is mainly used for shaping and mixing with other materials; the inorganic powder is mainly used as a filler, which can reduce costs and improve product stability; the compatibilizer is used to increase the interface bonding force between the resin and the inorganic powder; the toughening agent is used to increase the toughness and low-temperature performance of the floor; the lubricant is mainly used to improve the lubrication of the mechanical surface and the lubrication between the molecular chains of the material; the antioxidant is used to improve the resin oxidation phenomenon during the processing and later use; the nucleating agent is used to refine the grain size and improve warping shrinkage.

[0038] In summary, when manufacturing the floor, the main process of the preparation method of the substrate layer is: copolymer PP resin, LLDPE resin, compatibilizer, toughening agent, inorganic powder, lubricant, coupling agent, antioxidant, nucleating agent form a mixture, stir to fully mix the materials, and then extrude continuously through a twin-screw extruder, and control the thickness of the product through a thickness-setting roller to obtain a substrate layer. Then, the color film and wear-resistant layer are coated, and the surface of the substrate layer is pressed out with an embossing roller, and after roller traction and cooling, the parameters are set by the shearing machine, and the edges are trimmed and cut according to specifications to obtain a semi-finished product, and then the semi-finished product is coated and tempered, cured at 24°C for one day, and sliced, trimmed, and chamfered in turn to obtain a finished floor.

[0039] Specifically, the method for preparing the floor comprises the following steps:

[0040] S1: taking the raw materials of the substrate layer, putting them into a high-speed mixer for hot mixing, and then switching to a low-speed mixer for stirring and cooling to perform cold mixing; obtaining a premix of the substrate layer;

[0041] S2: putting the substrate layer premix obtained in step S1 into a twin-screw extruder, plasticizing and then extruding it, and then moving it to a thickness setting roller to adjust the substrate thickness to obtain a substrate layer;

[0042] S3: Then, a color film layer and an upper wear-resistant layer are sequentially coated on the base material layer in layers, and a lower wear-resistant layer is coated; an embossing roller is used to emboss to form a semi-finished flooring product;

[0043] S4: After the semi-finished floor is coated and tempered, it is punched, sliced, and trimmed to prepare the finished floor.

[0044] The high-speed mixer has a fast speed and can generate heat through stirring friction. The low-speed mixer is used for water cooling to avoid plasticization, agglomeration and high-temperature decomposition.

[0045] The upper wear-resistant layer, the lower wear-resistant layer and the color film layer can be synchronously bonded to the substrate using rollers, and the color film layer is compounded on the substrate layer by a traction roller and a flattening roller; the upper wear-resistant layer and the lower wear-resistant layer are compounded on the color film layer or under the substrate layer by a rubber roller. After the upper wear-resistant layer, the lower wear-resistant layer and the color film layer are compounded / bonded, the width of the substrate can be adjusted by the side knives on both sides, and the temperature of the plate can be reduced by air cooling, and the length of the plate can be controlled by an infrared cutting knife, and then the semi-finished flooring can be embossed. In the embodiment, the thickness of the upper wear-resistant layer and the lower wear-resistant layer is less than 0.3 mm, so the chamfering step is not used.

[0046] In step S1, the hot mix temperature of the high-speed mixer is 110°C to 180°C, the stirring speed is 300r / min to 400r / min (r / min is rpm), and the stirring time is 10min to 30min; the cold mix temperature of the low-speed mixer is 40°C to 60°C, the stirring speed is 100r / min to 200r / min, and the stirring time is 3min to 8min.

[0047] In step S2, the twin-screw extruder has six functional sections, which are the first zone feeding section, which can continuously feed; the second zone melting section, which can heat the material as a whole to form a molten state; the third zone plasticizing section, which plasticizes the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material; the fourth zone exhaust section, which can discharge the excess pores in the melt; the fifth zone mixing section, which fully mixes the raw materials; the sixth zone extrusion section, which is provided with a die, and the material inside the twin-screw extruder is extruded to form a floor base shape. The temperatures of the screw twin-screw zones are set to 190-120°C for zone 1, 195-190°C for zone 2, 190-180°C for zone 3, 185-175°C for zone 4, 180-170°C for zone 5, and 170-160°C for zone 6. Other settings of the twin-screw extruder include: the confluence core temperature is 180°C and the pressure is 0.1MPa. The main machine speed is 19.6r / min, the current is 220A; the feeding speed is 21r / min, the current is 0.2A; the die temperature is 220℃, and the extrusion width is 1050mm~1350mm.

[0048] The feeding section of the twin-screw extruder can continuously feed the material, the melting section can heat the material as a whole to form a molten state, the plasticizing section plasticizes the material, thereby reducing the hardness of the material, improving the toughness of the material, increasing the ductility and plasticity of the material, the exhaust section discharges the excess pores, the mixing section fully mixes it, and the extrusion section extrude the material inside the twin-screw extruder. The die of the twin-screw extruder can fix the size of the extruded material's width, thickness and other elements, so that the material takes shape.

[0049] Wherein, in step S2, the temperature of the upper and lower rollers of the thickness setting roller is 255°C.

[0050] In step S3, the upper and lower roller temperatures of the coating roller are 235° C. and 230° C. respectively, for laminating the upper wear-resistant layer and the color film; the upper and lower roller temperatures of the bottom coating roller are 225° C. for laminating the lower wear-resistant layer.

[0051] In step S4, the semi-finished product coating weight is 15 g, and water bath tempering is adopted, the tempering temperature is 35° C., and the curing is carried out for 24 hours.

[0052] The raw materials used to prepare the floor substrate in the following examples are all commercially available materials. For example:

[0053] The copolymer PP resin can be selected from any one or more of commercially available homopolymer PP resin, isotactic copolymer PP resin, and block copolymer PP resin.

[0054] The compatibilizer can be selected from any one or more of commercially available polyethylene grafted maleic anhydride (abbreviated as PE-g-MAH, CAS No.: 9006-26-2, such as PE 1040 of ExxonMobil, USA), polypropylene grafted maleic anhydride (abbreviated as PP-g-MAH, CAS: 25722-45-6, such as PO 1015 of ExxonMobil, USA), hydrogenated styrene-butadiene-styrene block copolymer grafted maleic anhydride (abbreviated as SEBS-g-MAH, such as FG1901 of Kraton, USA), and maleic anhydride grafted ethylene-octene copolymer (abbreviated as POE-g-MAH, such as R905 of Dow, USA).

[0055] The toughening agent includes any one or more of a block copolymer of styrene and butadiene (SBS for short, such as YH-792 of Yueyang Baling Petrochemical), a hydrogenated styrene-butadiene block copolymer (SEBS for short, such as YH-503T of Yueyang Baling Petrochemical), ethylene propylene diene monomer rubber (EPDM for short, such as 722P of Dow Chemical of the United States), and a polyolefin elastomer (POE for short, such as LEB-6550 of Lotte of South Korea).

[0056] The inorganic powder can be selected from any one or more of commercially available calcium carbonate (such as heavy calcium carbonate, light calcium carbonate), hydrotalcite, talcum powder, and mica powder. The particle size is preferably 10 μm to 50 μm.

[0057] The lubricant can be selected from any one or more of commercially available PE wax, montan wax, montan wax, calcium stearate, EBS (ie, ethylene bis stearamide), oleamide, and zinc stearate.

[0058] The coupling agent can be selected from any one or more of commercially available aluminate coupling agents (such as aluminate coupling agents F-1, DL-411), titanate coupling agents (such as titanate coupling agent NDZ-201), and silane coupling agents (such as silane coupling agents KH-550, KH-560, KH-570).

[0059] The antioxidant can be selected from any one or more of commercially available hindered phenols (such as antioxidant 1010, Irganox 1098), aromatic amines (such as butylated hydroxyanisole (BHA), phosphites (such as triphenyl phosphite (TPP, antioxidant 168), and sulfur-containing esters (such as distearyl thiodipropionate (DSTP).

[0060] The nucleating agent can be selected from any one or more of commercially available amide compounds (such as P-26 from Jining Beijia Polymer Materials Co., Ltd.), sorbitol benzyl derivatives (such as dibenzylidene sorbitol, i.e. DBS), aromatic carboxylic acid metal compounds (such as Maxstab RY 501 from Shanghai Qirun New Materials Co., Ltd.), organic phosphates (such as Maxstab RY511 from Shanghai Qirun New Materials Co., Ltd.), and sodium benzoate.

[0061] Example 1 Preparation of floor substrate and floor

[0062] This embodiment aims to prepare the substrate layer of the floor, and prepare Figure 1 The floor shown in the figure is composed of an upper wear-resistant layer 1, a color film layer 2, a base material layer 3, and a lower wear-resistant layer 4. The gaps between the layers in the figure are only to show the layering relationship more intuitively, and do not represent the existence of gaps between the layers. This is determined by the bonding process.

[0063] In this embodiment, four kinds of substrate layers are prepared, and the ingredients are shown in Table 1. The steps for preparing the substrate layer are as described above, including:

[0064] S1: taking the raw materials of the substrate layer, putting them into a high-speed mixer for hot mixing, and then switching to a low-speed mixer for stirring and cooling to perform cold mixing; obtaining a premix of the substrate layer;

[0065] S2: putting the substrate layer premix obtained in step S1 into a twin-screw extruder, plasticizing and then extruding it, and then moving it to a thickness setting roller to adjust the substrate thickness to obtain a substrate layer;

[0066] In the substrate layer preparation process of Experimental Examples 1 to 4, the confluence core temperature of the twin-screw extruder was 180°C and the pressure was 0.1 MPa. The main engine speed was 19.6 r / min and the current was 220 A; the feed speed was 21 r / min and the current was 0.2 A; and the die temperature was 220°C. Other process parameters are shown in Table 2.

[0067] Table 1 Ingredients of the base material layer of Experimental Examples 1 to 4 (parts by weight)

[0068]

[0069]

[0070] Table 2 Process parameters for preparing the substrate layer of Experimental Examples 1 to 4

[0071]

[0072] Note: “±” indicates the temperature fluctuation range.

[0073] This embodiment further comprises four substrate layers. Figure 1The structure shown is used to prepare four kinds of floors (i.e., four kinds of floors prepared using the substrate layers of Experimental Examples 1 to 4, respectively). The color film layer, the upper wear-resistant layer, and the lower wear-resistant layer of the four kinds of floors are the same. The preparation method of the floor comprises the following steps:

[0074] S3: sequentially coating the base material layer with a color film layer and an upper wear-resistant layer, and coating the lower wear-resistant layer; embossing with an embossing roller to form a semi-finished flooring product;

[0075] S4: After the semi-finished floor is coated and tempered, it is punched, sliced, and trimmed to prepare the finished floor.

[0076] In step S3, the mold temperature controller controls the roller temperature, and the temperature of the machine roller area is 255°C for the upper and lower rollers of the thickness roller; the upper and lower rollers of the film roller are 235°C and 230°C respectively; the upper and lower rollers of the bottom film roller are 225°C.

[0077] In step S4, the semi-finished product coating weight is 15 g, and water bath tempering is adopted, the tempering temperature is 35° C., and the curing is carried out for 24 hours.

[0078] Example 2 Performance Test of Floor

[0079] In this example, 6 kinds of comparative substrate layers (Comparative Examples 1 to 6) were prepared and Figure 1 Six kinds of comparative floorings were prepared with the structures shown and the aforementioned thickness parameters of each layer. The ingredients of the six comparative substrate layers are shown in Table 3. The preparation methods of the six comparative substrate layers were in accordance with the preparation method of Experimental Example 1 of Example 1. The six comparative floorings were respectively made with the substrate layers of Comparative Examples 1 to Comparative Examples 6, and the preparation methods of the floorings were the same as those of Example 1.

[0080] Table 3 Ingredients of the substrate layer of Comparative Examples 1 to 6 (parts by weight)

[0081]

[0082]

[0083] Performance tests were performed on four types of floorings prepared from the substrate layers of Experimental Examples 1 to 4 of Example 1 and Example 2 and six types of floorings prepared from the substrate layers of Comparative Examples 1 to 6. The test reference standards and methods are as follows:

[0084] Warpage: Tested in accordance with ISO24342 standard. Cut the sample into a 250mm×250mm square, place it on a flat table, and use a feeler gauge to test the four corners of the sample one by one. The test result is the maximum value among the four corners.

[0085] Heat shrinkage: Tested in accordance with ISO24342 standard. Cut the sample into a 250mm×250mm square, measure the length and width of the sample (all four sides need to be measured and recorded, length is L10, L20, width is W10, W20), place the sample in an 80℃ oven, take it out after 6 hours and place it in the laboratory for 3 hours, and then test the length and width of the sample after standing (length is L11, L21, width is W11, W21). Calculate, length: [(L11+L21) / 2-(L10+L20) / 2] / [(L10+L20) / 2]; width: [(W11+W21) / 2-(W10+W20) / 2] / [(W10+W20) / 2], and select the maximum value of the test result. .

[0086] Thermal expansion test: Cut a 180mm×1220mm sample, place it in a drying room, and set the drying room temperature to 20℃. After the drying room reaches the set temperature, keep it warm for 3h, measure the length and width, and record the length as L10 and L20, and the width as W10 and W20. Then set the drying room temperature to 70℃, keep it warm for 3h after reaching the set temperature, measure the length and width, and record the length as L11 and L21, and the width as W11 and W21. Calculate the experimental data, the thermal expansion coefficient of length is: {[(L11+L21) / 2-(L10+L20) / 2] / [(L10+L20) / 2] / 50}×100000; the thermal expansion coefficient of width is: {[(W11+W21) / 2-(W10+W20) / 2] / [(W10+W20) / 2] / 50}×100000, and the maximum value is selected for the test result.

[0087] Drop ball impact: Tested in accordance with EN13329 standard. Place a 300mm×250mm sample on the chassis of the drop ball impact tester and fix it with screws. Use a 2280g ball to drop from a height of 1500mm for impact test.

[0088] Lighting test: Cut a 180mm×1220mm sample, place it in a lighting laboratory, set the lighting temperature to 70℃, and light for 3 hours.

[0089] Elastic modulus and static bending strength: Tested according to GB17657 standard. Cut a 50mm×150mm sample, measure the sample thickness, place the sample on the support roller of the universal mechanical testing machine, input the sample thickness and then test.

[0090] Table 4 Floor performance prepared by substrate layer of Experimental Examples 1 to 4

[0091]

[0092]

[0093] Table 5 Performance of floors prepared from the substrate layers of Comparative Examples 1 to 6

[0094]

[0095] It can be seen from Table 4 that the floor prepared by the substrate layer of the present invention (Experimental Examples 1 to 4) has a warpage of ≤0.7 mm, a thermal shrinkage of ≤0.05%, and a thermal expansion coefficient of ≤3.5x10 -5 , no cracking in falling ball impact, no arching in light test, elastic modulus ≥3700MPa, static bending strength ≥24MPa, the comprehensive performance indicators are better than the floors prepared by the substrate layers of Comparative Examples 1 to 6 (Table 5).

[0096] The above embodiments are only used to illustrate the technical concept and features of the present invention, and are not intended to limit the protection scope of the present invention. Any similar replacement or transformation made without creative labor according to the technical solution of the present invention should fall within the protection scope of the present invention.

Claims

1. A low-warping and anti-deformation floor, comprising, from top to bottom, an upper wear-resistant layer, a color film layer, a substrate layer and a lower wear-resistant layer, characterized in that: The substrate layer is made of the following raw materials in parts by weight: 50-100 parts of copolymer PP resin, 10-50 parts of LLDPE resin, 2-10 parts of compatibilizer, 10-20 parts of toughening agent, 50-300 parts of inorganic powder, 1-3 parts of lubricant, 1-5 parts of coupling agent, 0.5-2 parts of antioxidant and 0.1-1 parts of nucleating agent.

2. The low-warping and anti-deformation floor according to claim 1, characterized in that: The copolymer PP resin is selected from at least one of homopolymer PP resin, isotactic copolymer PP resin and block copolymer PP resin.

3. The low warping and deformation resistant floor according to claim 1, characterized in that: The compatibilizer is selected from at least one of polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, hydrogenated styrene-butadiene-styrene block copolymer grafted with maleic anhydride, and maleic anhydride grafted with ethylene-octene copolymer.

4. The low warping and deformation resistant floor according to claim 1, characterized in that: The toughening agent is selected from at least one of a block copolymer of styrene and butadiene, a hydrogenated styrene-butadiene block copolymer, ethylene propylene diene monomer rubber, and a polyolefin elastomer.

5. The low warping and deformation resistant floor according to claim 1, characterized in that: The inorganic powder is selected from at least one of calcium carbonate, hydrotalcite, talcum powder and mica powder.

6. The low-warping and deformation-resistant floor according to claim 5, characterized in that: The particle size of the inorganic powder is 10 μm to 50 μm.

7. The low warping and deformation resistant floor according to claim 1, characterized in that: The lubricant is selected from at least one of PE wax, montan wax, montan wax, calcium stearate, EBS, oleamide and zinc stearate.

8. The low warping and deformation resistant floor according to claim 1, characterized in that: The coupling agent is selected from at least one of an aluminate coupling agent, a titanate coupling agent, and a silane coupling agent.

9. The low-warping and deformation-resistant floor according to claim 1, characterized in that: The antioxidant is selected from at least one of hindered phenol antioxidants, aromatic amine antioxidants, phosphite antioxidants, and sulfur-containing ester antioxidants.

10. The low warping and deformation resistant floor according to claim 1, characterized in that: The nucleating agent is selected from at least one of a fatty carboxylic acid metal compound, a sorbitol benzyl derivative, an aromatic carboxylic acid metal compound, an organic phosphate, and sodium benzoate.

11. The low-warping and deformation-resistant floor according to any one of claims 1 to 10, characterized in that: The preparation method of the substrate layer comprises the following steps: S1: taking the raw materials of the substrate layer, putting them into a high-speed mixer for hot mixing, and then switching to a low-speed mixer for stirring and cooling to perform cold mixing; obtaining a premix of the substrate layer; S2: The substrate layer premix obtained in step S1 is put into a twin-screw extruder, extruded after plasticization, and then moved to a thickness-fixing roller to adjust the substrate thickness to obtain a substrate layer.

12. The low-warping and deformation-resistant floor according to claim 11, characterized in that: In step S1, the hot mix temperature of the high-speed mixer is 110°C to 180°C, the stirring speed is 300 r / min to 400 r / min, and the stirring time is 10 min to 30 min; the cold mix temperature of the low-speed mixer is 40°C to 60°C, the stirring speed is 100 r / min to 200 r / min, and the stirring time is 3 min to 8 min.

13. The low warping and deformation resistant floor according to claim 11, characterized in that: In step S2, the twin-screw extruder has six functional sections, which are the first section feeding section, which can continuously feed the material; the second section melting section, which can heat the material as a whole to form a molten state; the third section plasticizing section, which plasticizes the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material; the fourth section exhaust section, which can discharge the excess pores in the melt; the fifth section mixing section, which fully mixes the raw materials; the sixth section extrusion section, which is provided with a die, and the material inside the twin-screw extruder is extruded to form a floor base shape. The temperatures of the screw twin-screw zones are set to 190~120℃ for zone 1, 195~190℃ for zone 2, 190~180℃ for zone 3, 185~175℃ for zone 4, 180~170℃ for zone 5, and 170~160℃ for zone 6. Other settings of the twin-screw extruder include: the confluence core temperature is 180°C, the pressure is 0.1 MPa, the main engine speed is 19.6r / min, the current is 220A, the feed speed is 21r / min, the current is 0.2A, the die temperature is 220°C, the extrusion width is 1050mm~1350mm, and the temperature of the upper and lower rollers of the thickness setting roller in step S2 is 255°C.

14. The low warping and deformation resistant floor according to claim 11, characterized in that: The method for preparing the floor comprises the following steps: S3: sequentially coating the base material layer with a color film layer and an upper wear-resistant layer, and coating the lower wear-resistant layer; and embossing with an embossing roller to form a semi-finished flooring product; S4: After the semi-finished floor is coated and tempered, it is punched, sliced, and trimmed to prepare the finished floor.

15. The low-warping and deformation-resistant floor according to claim 14, characterized in that: In step S3, the upper and lower roller temperatures of the film attaching roller are 235°C and 230°C respectively; the upper and lower roller temperatures of the bottom film coating roller are 225°C.

16. The low-warping and deformation-resistant floor according to claim 14, characterized in that: In step S4, the coating weight of the semi-finished product is 15 g, and water bath tempering is adopted, the tempering temperature is 35° C., and the curing is performed for 24 hours.

17. Use of the low-warping and deformation-resistant flooring according to any one of claims 1 to 10 in the preparation of flooring.

Images