Low-warping and deformation-resistant floor and its use

Abstract

The present invention relates to the technical field of flooring, and specifically relates to a low-warping, deformation-resistant flooring and its uses. The flooring comprises, from top to bottom, an upper wear-resistant layer, a color film, a substrate layer, and a lower wear-resistant layer. The substrate layer is made from the following raw materials: copolymerized PP resin, LLDPE resin, a compatibilizer, a toughening agent, an inorganic powder, a lubricant, a coupling agent, an antioxidant, and a nucleating agent. These raw materials are hot-mixed in a high-speed blender and cold-mixed in a low-speed blender, then extruded using a twin-screw extruder and the thickness adjusted. Multi-layer flooring prepared using this substrate layer has advantages such as good dimensional stability, excellent low-temperature performance, and a simple process.

Description

Technical Field

[0001] The present 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 flooring is a lightweight floor decoration material. It refers to flooring produced from polyvinyl chloride materials. Specifically, it refers to polyvinyl chloride and its copolymer resins as the main raw materials, with the addition of fillers, plasticizers, stabilizers, colorants and other auxiliary ingredients. Since the subsequent processing of polyvinyl chloride materials is inconvenient and does not conform to the concepts of environmental protection and sustainable development, 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, as well as 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 response to the above problems, the present invention aims to provide a low-warping and deformation-resistant floor to overcome the problems of poor warping and shrinkage, poor low-temperature performance, and other issues of traditional PP flooring. To solve the above technical problems, the following technical solutions are adopted:

[0005] First, the present invention provides a low-warping and deformation-resistant floor, which includes, from top to bottom, an upper wear-resistant layer, a color film layer, a substrate layer and a lower wear-resistant layer. 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 homopolymer PP resin, isotactic copolymer PP resin and 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: Take the raw materials of the base material layer, put them into a high-speed mixer and stir them for hot mixing, then transfer them to a low-speed mixer and stir and cool them for cold mixing to obtain a base material premix;

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

[0018] Preferably, in step S1, the hot mix temperature of the high-speed stirrer 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 stirrer 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, namely, a feeding section (zone 1) for continuous feeding; a melting section (zone 2) for heating the entire material to a molten state; a plasticizing section (zone 3) for plasticizing the material, thereby reducing its hardness, improving its toughness, and increasing its ductility and plasticity; a venting section (zone 4) for removing excess air pores from the melt; a mixing section (zone 5) for thorough mixing of the raw materials; and an extrusion section (zone 6) with a die for extruding the material inside the twin-screw extruder to form the floor base shape. The temperatures of the twin-screw zones are set as follows: 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 a confluence core temperature of 180°C and a pressure of 0.1 MPa. The main engine 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℃, the extrusion width is 1050mm~1350mm; the temperature of the upper and lower rollers of the thickness setting roller in step S2 is 255℃.

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

[0021] S3: Laying a color film layer, an upper wear-resistant layer, and a lower wear-resistant layer on the base material layer in layers; 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 the product is tempered in a water bath at a tempering temperature of 35° C. for 24 hours.

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

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

[0027] (1) The floor base material is a blend of copolymerized 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 improve the bonding strength between the base material 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 Schematic diagram of the structure 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] The following combination Figure 1 It is obvious that the terms about direction in the following embodiments, such as "up", "down", "left", "right", etc., are based on Figure 1 The orientation shown is for installation of the floor and does not represent the orientation of the product when it is placed.

[0032] Depend on Figure 1 As can be seen, the flooring of the present invention comprises, from top to bottom, an upper wear-resistant layer, a color film layer, a base material layer, and a lower wear-resistant layer. For clarity in the description of the specific embodiments, the following examples of the present invention have a base material layer thickness of 4 mm, an upper wear-resistant layer and a lower wear-resistant layer thickness of 0.2 mm, and a color film layer thickness of 0.2 mm. The thickness of each layer depends on user needs and does not affect the effectiveness of the present invention. Therefore, it is only used to illustrate the specific embodiments and is not to be considered as limiting the scope of protection. The thickness of each layer of the comparative flooring is similar.

[0033] Color film layers are primarily used to color floors. They come in two types: standard color film and online-matching color film. Online-matching color film features black markings. Floor color film layers use a colored film as a base material and are applied to specific areas of the floor through lamination technology, achieving the desired effect. They also provide moisture-proofing properties. Floor color film can be made from materials such as polyvinyl alcohol, polyester, matte coating agents, and PVC.

[0034] The wear-resistant layer is primarily used to protect the color film and the substrate from wear and corrosion over time. It comes in two finishes: glossy and embossed. Different wear-resistant layers can have varying thicknesses and can be made with different oils. The wear-resistant layer can be made from materials such as melamine resin, 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-to-line 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 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 embodiment 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 as follows by weight: 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 part of nucleating agent.

[0037] The copolymer PP resin is a resin material, which is mainly used for shaping and mixing and connecting 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 interfacial 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 process and later use; the nucleating agent is used to refine the grain size and improve warping shrinkage.

[0038] In summary, the main process for preparing the substrate layer in flooring manufacturing is as follows: a mixture of copolymerized PP resin, LLDPE resin, compatibilizer, toughening agent, inorganic powder, lubricant, coupling agent, antioxidant, and nucleating agent is prepared. The mixture is stirred to ensure thorough mixing, and then continuously extruded through a twin-screw extruder. The thickness of the product is controlled by a thickness-setting roller to produce the substrate layer. A color film and a wear-resistant layer are then applied, and the surface of the substrate layer is textured with an embossing roller. After roller traction and cooling, the substrate layer is set on a shearing machine, trimmed, and cut to specifications to produce a semi-finished product. The semi-finished product is then coated and tempered, cured at 24°C for one day, and then sliced, trimmed, and chamfered to produce the finished flooring.

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

[0040] S1: Take the raw materials of the base material layer, put them into a high-speed mixer and stir them for hot mixing, then transfer them to a low-speed mixer and stir and cool them for cold mixing to obtain a base material premix;

[0041] S2: The substrate layer premix obtained in step S1 is fed into a twin-screw extruder, plasticized and then extruded, and then moved to a thickness-setting roller to adjust the substrate thickness to obtain a substrate layer;

[0042] S3: Then, a color film layer, an upper wear-resistant layer, and a lower wear-resistant layer are sequentially applied on the base material layer in layers; an embossing roller is used to emboss the floor 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, while the low-speed mixer is used for water cooling to avoid plasticization, agglomeration, and high-temperature decomposition.

[0045] The upper and lower wear-resistant layers, along with the color film layer, are simultaneously laminated to the substrate using rollers. The color film layer is laminated onto the substrate using traction and flattening rollers. The upper and lower wear-resistant layers are then laminated to the color film layer or underneath the substrate using rubber rollers. After lamination / bonding of the upper and lower wear-resistant layers, the substrate width can be adjusted using side cutters, the panel temperature can be lowered using air cooling, and the panel length can be controlled using infrared cutting knives. Embossed flooring is then completed to form the semi-finished flooring product. In this embodiment, the thickness of the upper and lower wear-resistant layers is less than 0.3 mm, so chamfering is not required.

[0046] In step S1, the hot mix temperature of the high-speed stirrer 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 stirrer 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: Zone 1 (feeding section), which continuously feeds the material; Zone 2 (melting section), which heats the entire material to a molten state; Zone 3 (plasticizing section), which plasticizes the material, thereby reducing its hardness, increasing its toughness, and increasing its ductility and plasticity; Zone 4 (venting section), which removes excess air pores from the melt; Zone 5 (mixing section), which thoroughly mixes the raw materials; and Zone 6 (extrusion section), which has a die that extrudes the material inside the twin-screw extruder to form the floor base. The temperatures of the twin-screw zones are set as follows: Zone 1 (190-120°C), Zone 2 (195-190°C), Zone 3 (190-180°C), Zone 4 (185-175°C), Zone 5 (180-170°C), and Zone 6 (170-160°C). Other settings for the twin-screw extruder include a confluence core temperature of 180°C and a pressure of 0.1 MPa. 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 a twin-screw extruder can continuously feed the material. The melting section can heat the entire material to form a molten state. The plasticizing section plasticizes the material, thereby reducing the material's hardness, improving its toughness, and increasing its ductility and plasticity. The venting section removes excess air holes. The mixing section fully mixes the material. The extrusion section squeezes the material out of the twin-screw extruder. The die of the twin-screw extruder can fix the dimensions of the extruded material, such as its width and thickness, to give the material its initial shape.

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

[0050] In step S3, the upper and lower roller temperatures of the laminating 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 film laminating 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 at a tempering temperature of 35° C. for 24 h.

[0052] The raw materials used in the following examples to prepare the floor substrates 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 resins, isotactic copolymer PP resins, and block copolymer PP resins.

[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, such as YH-792 of Yueyang Baling Petrochemical), a hydrogenated styrene-butadiene block copolymer (SEBS, such as YH-503T of Yueyang Baling Petrochemical), an ethylene propylene diene monomer (EPDM, such as 722P of Dow Chemical, USA), and a polyolefin elastomer (POE, such as LEB-6550 of Lotte, 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, talc powder, and mica powder, and 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 bisstearamide), 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 agent 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, and 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 base material layer of the floor, and prepare Figure 1 The floor shown here consists 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 image are simply to illustrate the layering relationship more intuitively, and do not represent actual gaps between the layers. This is determined by the lamination process.

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

[0064] S1: Take the raw materials of the base material layer, put them into a high-speed mixer and stir them for hot mixing, then transfer them to a low-speed mixer and stir and cool them for cold mixing to obtain a base material premix;

[0065] S2: The substrate layer premix obtained in step S1 is fed into a twin-screw extruder, plasticized and then extruded, and then moved to a thickness-setting roller to adjust the substrate thickness to obtain a substrate layer;

[0066] In the substrate layer preparation processes of Experimental Examples 1 to 4, the converging core temperature of the twin-screw extruder was 180°C, the pressure was 0.1 MPa, the main engine speed was 19.6 rpm, the current was 220 A, the feed speed was 21 rpm, 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 based on the four substrate layers, Figure 1Four types of flooring were prepared using the structures shown (i.e., four types of flooring were prepared using the substrate layers of Experimental Examples 1 to 4, respectively). The color film layer, upper wear-resistant layer, and lower wear-resistant layer of the four types of flooring were identical. The preparation method of the flooring included the following steps:

[0074] S3: Laying a color film layer, an upper wear-resistant layer, and a lower wear-resistant layer on the base material layer in layers; 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. The temperatures of the upper and lower rollers of the thickness roller are 255°C; the upper and lower rollers of the film roller are 235°C and 230°C respectively; and 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 at a tempering temperature of 35° C. for 24 h.

[0078] Example 2 Performance Test of Floor

[0079] This example prepared 6 kinds of comparative substrate layers (Comparative Examples 1 to 6), and Figure 1 Six comparative floorings were prepared using the structures shown and the aforementioned layer thickness parameters. The ingredients for the six comparative substrate layers are shown in Table 3. The six comparative substrate layers were prepared according to the method described in Experimental Example 1 of Example 1. The six comparative floorings were made using the substrate layers of Comparative Examples 1 to 6, respectively, using the same method as in Example 1.

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

[0081]

[0082]

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

[0084] Warpage: Tested in accordance with ISO 24342. Cut the sample into a 250mm x 250mm square, place it on a flat surface, and use a feeler gauge to measure each of the four corners. The maximum value among the four corners is used as the test result.

[0085] Thermal Shrinkage: Tested in accordance with ISO 24342. Cut the sample into a 250mm x 250mm square. Measure the length and width of the sample (measure and record all four sides, length L10 and L20, width W10 and W20). Place the sample in an 80°C oven for 6 hours. After 6 hours, remove it from the oven and allow it to rest in the laboratory for 3 hours. After resting, measure the length and width of the sample (length L11 and L21, width W11 and W21). Calculate the length: [(L11 + L21) / 2 - (L10 + L20) / 2] / [(L10 + L20) / 2]; the width: [(W11 + W21) / 2 - (W10 + W20) / 2] / [(W10 + W20) / 2]. The maximum value is used.

[0086] Thermal Expansion Test: Cut a 180mm x 1220mm sample and place it in a drying oven at 20°C. After the oven reaches the set temperature, hold it for 3 hours. Measure the length and width, recording L10 and L20 for the lengths and W10 and W20 for the widths. Next, set the oven temperature to 70°C and hold it for 3 hours. Measure the length and width, recording L11 and L21 for the lengths and W11 and W21 for the widths. Calculate the experimental data: the coefficient of thermal expansion for length is: {[(L11+L21) / 2-(L10+L20) / 2] / [(L10+L20) / 2] / 50}×100,000; the coefficient of thermal expansion for width is: {[(W11+W21) / 2-(W10+W20) / 2] / [(W10+W20) / 2] / 50}×100,000. The maximum value is selected as the test result.

[0087] Drop ball impact: Tested in accordance with EN13329. A 300mm x 250mm sample is placed on the chassis of the drop ball impact tester and secured with screws. A 2280g ball is dropped from a height of 1500mm for impact testing.

[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 flexural strength: Tested in accordance with GB17657. Cut a 50mm x 150mm sample, measure the sample thickness, place the sample on the support roller of a universal mechanical testing machine, and enter the sample thickness before testing.

[0090] Table 4 Performance of floors prepared from substrate layers of Experimental Examples 1 to 4

[0091]

[0092]

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

[0094]

[0095] As shown in Table 4, the flooring prepared from 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 scope of protection of the present invention. Any similar replacement or transformation based on the technical solution of the present invention without creative work should fall within the scope of protection of the present invention.

Claims

1. A low-warping and deformation-resistant floor, comprising, from top to bottom, an upper wear-resistant layer, a color film layer, a base material 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 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 part of nucleating agent; the toughening agent is selected from at least one of a block copolymer of styrene and butadiene, a hydrogenated styrene-butadiene block copolymer, EPDM rubber, and a polyolefin elastomer; the lubricant is selected from at least one of PE wax, montan wax, montan wax, calcium stearate, EBS, oleamide, and zinc stearate; the coupling agent is selected from at least one of an aluminate coupling agent, a titanate coupling agent, and a silane coupling agent; the PP resin is selected from one of K8303 PP resin, V30G PP resin, and Z30S PP resin; the LLDPE resin is UR644 LLDPE resin; 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; the inorganic powder is selected from at least one of calcium carbonate, hydrotalcite, talc powder, and mica powder; the particle size of the inorganic powder is 10 μm to 50 μm; the antioxidant is selected from at least one of hindered phenol antioxidants, aromatic amine antioxidants, phosphite antioxidants, and sulfur-containing ester antioxidants; and 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.

2. The low-warping and deformation-resistant floor according to claim 1, characterized in that: The preparation method of the substrate layer comprises the following steps: S1: Take the raw materials of the base material layer, put them into a high-speed mixer and stir them for hot mixing, then transfer them to a low-speed mixer and stir and cool them for cold mixing to obtain a base material premix; S2: The substrate layer premix obtained in step S1 is fed into a twin-screw extruder, plasticized and then extruded, and then moved to a thickness-setting roller to adjust the substrate thickness to obtain a substrate layer.

3. The low-warping and deformation-resistant floor according to claim 2, characterized in that: In step S1, the hot mix temperature of the high-speed stirrer 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 stirrer 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.

4. The low-warping and deformation-resistant floor according to claim 2, characterized in that: In the step S2, the twin-screw extruder has six functional sections, which are, in order, a feeding section in the first zone, which can continuously feed the material; a melting section in the second zone, which can heat the material as a whole to form a molten state; a plasticizing section in the third zone, 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; a venting section in the fourth zone, which can discharge excess pores in the melt; a mixing section in the fifth zone, which fully mixes the raw materials; an extrusion section in the sixth zone, 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 be 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: a confluence core temperature of 180℃, a pressure of 0.1 Mpa; main engine speed is 19.6r / min, current is 220A; feed speed is 21r / min, current is 0.2A; die temperature is 220℃, extrusion width is 1050 mm~1350mm; the temperature of the upper and lower rollers of the thickness setting roller in step S2 is 255℃.

5. The low-warping and deformation-resistant floor according to claim 2, characterized in that: The method for preparing the floor comprises the following steps: S3: Laying a color film layer, an upper wear-resistant layer, and a lower wear-resistant layer on the base material layer in layers; 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.

6. The low-warping and deformation-resistant floor according to claim 5, characterized in that: In step S3, the upper and lower roller temperatures of the laminating 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 film laminating roller are 225°C, for laminating the lower wear-resistant layer.

7. The low-warping and deformation-resistant floor according to claim 5, characterized in that: In step S4, the semi-finished product has a coating weight of 15 g and is tempered in a water bath at a tempering temperature of 35° C. for 24 hours.

8. Use of the low-warping and deformation-resistant flooring according to any one of claims 1 to 7 in the preparation of flooring.

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