Foamed floor and method for manufacturing the same

Abstract

The present application relates to a kind of foamed floor and its preparation method, including foamed surface layer and foamed bottom layer;The foamed surface layer, by weight parts, including the following raw materials: PET resin 70~90 parts, heavy calcium carbonate 20~30 parts, modifier 12~20 parts, chain extender 10~16 parts, foaming agent 2~10 parts, internal lubricant 0.5~3 parts, external lubricant 0.5~3 parts;The foamed bottom layer, by weight parts, including the following raw materials: PET resin 30~40 parts, modifier 6~10 parts, chain extender 2~8 parts, foaming agent 1~5 parts, internal lubricant 0.5~3 parts, external lubricant 0.5~3 parts.The foamed floor of the present application adopts the way of foamed surface layer and foamed bottom layer combination, compared with traditional single-layer floor, the floor of double-layer structure is not easy to warp deformation with seasonal temperature change, not easy to appear during use Bulge, with good mechanical stability.

Description

Technical Field

[0001] This invention relates to the field of flooring, and in particular to a foamed flooring and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) flooring is widely used as a flooring material due to its ultra-lightweight, ultra-thin, and highly wear-resistant properties, and is widely applied in homes, hospitals, schools, office buildings, factories, public places, supermarkets, commercial spaces, and other locations. However, as the international community places increasing emphasis on environmental protection, PVC materials are prohibited or restricted in some countries, especially because they produce acidic substances during combustion, which is detrimental to environmental protection.

[0003] Polyethylene terephthalate (PET) foam is a closed-cell thermoplastic renewable polymer foam with excellent fire resistance, smoke resistance, and toxicity resistance. It also possesses outstanding mechanical properties and fatigue resistance, is chemically stable, UV resistant, and has low water absorption. Furthermore, PET sheets can be recycled multiple times, making it a viable alternative to PVC sheets. In practical applications, because PET foam is typically produced through foaming molding, it is mostly used in single-layer structures. However, single-layer structures are more prone to warping and deformation due to seasonal temperature changes. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a foamed floor and its preparation method. The foamed floor combines a foamed surface layer and a foamed bottom layer. The double-layer structure of the floor is less prone to warping and deformation due to seasonal temperature changes, and it is less likely to bulge during use, exhibiting good mechanical stability.

[0005] To address the aforementioned technical problems, one objective of this invention is to provide a foamed flooring, comprising a foamed surface layer and a foamed bottom layer. The foamed surface layer, by weight, comprises the following raw materials: 70-90 parts PET resin, 20-30 parts heavy calcium carbonate, 12-20 parts modifier, 10-16 parts chain extender, 2-10 parts foaming agent, 0.5-3 parts internal lubricant, and 0.5-3 parts external lubricant. The foamed bottom layer, by weight, comprises the following raw materials: 30-40 parts PET resin, 6-10 parts modifier, 2-8 parts chain extender, 1-5 parts foaming agent, 0.5-3 parts internal lubricant, and 0.5-3 parts external lubricant.

[0006] Furthermore, the modifier is a mixture of an acrylate-glycidyl ester bifunctionalized ethylene elastomer and an ethylene-methyl acrylate-glycidyl methacrylate copolymer.

[0007] Furthermore, the mass ratio of the ethylene-methyl acrylate-glycidyl methacrylate copolymer to the acrylate-glycidyl acrylate difunctionalized ethylene elastomer is (6-8):(1-2).

[0008] Furthermore, the monomer ratio in the ethylene-methyl acrylate-glycidyl methacrylate copolymer is 10:40:50.

[0009] Furthermore, the ratio of acrylate to glycidyl ester in the acrylate-glycidyl ester bifunctionalized vinyl elastomer is 30:70.

[0010] Furthermore, the chain extender includes at least one of ethylenediamine polyether tetraol, polyoxypropylene triol, and styrene-methyl methacrylate-glycidyl methacrylate copolymer.

[0011] Furthermore, the monomer ratio in the styrene-methyl methacrylate-glycidyl methacrylate copolymer is 10:40:50.

[0012] Furthermore, the foaming agent includes any one of azodicarbonamide, carbon dioxide, and cyclopentane.

[0013] Furthermore, the internal lubricant includes any one of stearic acid and siloxane.

[0014] Furthermore, the external lubricant includes PE wax.

[0015] Furthermore, a colored wear-resistant layer is also bonded to the surface of the foamed surface layer.

[0016] A second objective of this invention is to provide a method for preparing the aforementioned flooring:

[0017] S1. Take heavy calcium carbonate, modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140-150℃ to obtain foamed surface layer mixture; take modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140-150℃ to obtain foamed bottom layer mixture.

[0018] S2. When the foamed surface layer mixture and the foamed bottom layer mixture from step S1 are cooled to 60-70°C, they are respectively fed to a screw extruder.

[0019] S3. The foamed surface layer mixture and the foamed bottom layer mixture are extruded separately using a screw extruder. Foaming agents for the foamed surface layer and the foamed bottom layer are added separately during extrusion. The extrusion temperature of the screw extruder is set as follows: Zone 1 260~270℃, Zone 2 275~290℃, Zone 3 270~280℃, Zone 4 255~265℃, Zone 5 255~265℃, Zone 6 255~265℃, Connector 255~265℃, Die Head Zone 255~265℃.

[0020] S4. The extruded foamed surface layer mixture and foamed bottom layer mixture are adjusted in flow rate and thickness by melt pump and distributor, and then enter the mold for in-mold compounding and extrusion molding.

[0021] S5. After extrusion in step S4, the foamed surface layer and the foamed bottom layer become one piece; at the same time, a colored wear-resistant layer is bonded to the surface of the foamed surface layer, and after cooling, it is cut to obtain the foamed floor.

[0022] Furthermore, the thickness of the foamed bottom layer is 0.3-0.7 mm.

[0023] Through the above technical solutions, (1) PET resin is a polymer with strong water absorption, and the condensation reaction of synthesizing PET is a reversible reaction. Therefore, if there is moisture in PET during melt extrusion, it will lead to hydrolysis of PET molecules. Hydrolysis will lead to a decrease in the relative molecular mass of PET, a decrease in physical properties, especially impact strength, and defects such as bubbles, streaks, and blurring will occur in the sheet. Therefore, PET must be dried before melt extrusion to make its moisture content less than 0.005%. PET will age during the drying process. If the drying is incomplete, it will hydrolyze during processing. The effects of the drying process on it are: using a large air flow rate, a high drying temperature, and a long drying time will cause aging; using a low drying temperature, a low air flow rate, and a short drying time will cause hydrolysis. Therefore, the appropriate air flow rate is 0.62 m 3 / min, drying time is 5-6h. (2) PET resin is a crystalline resin with a melting point of 242-250℃. Therefore, the working temperature must be higher than its melting point. At the same time, PET is easily thermally degraded above 280℃, so the material temperature cannot exceed 280℃. A barrier-type screw extruder is used. The second zone is the starting section of the compression section. The temperature should be set higher so that excessive frictional heat will not be generated due to excessive shearing, which will cause PET to age. The die temperature is set about 5℃ lower than the material temperature, and the two ends are slightly higher than the middle.

[0024] Beneficial effects of the present invention

[0025] 1. The foamed flooring of the present invention adopts a combination of foamed surface layer and foamed bottom layer. Compared with traditional single-layer flooring, the double-layer structure flooring is not easy to warp and deform with seasonal temperature changes, and is not prone to bulging during use, thus having good mechanical stability.

[0026] 2. The foamed flooring of the present invention adopts a combination of a foamed surface layer and a foamed bottom layer. On the one hand, by adjusting the balance effect of the foamed bottom layer on the foamed surface layer, the problem of bending and deformation caused by heat on the coated board is avoided; on the other hand, the pure resin layer of the bottom layer has a large repulsion of water vapor, effectively preventing water vapor from penetrating and improving the stability of the foamed flooring. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the experimental materials and reagents used in the following examples are commercially available. All quantitative experiments in the following examples were performed in triplicate, and the data are the average of the three replicates or the average ± standard deviation.

[0029] Furthermore, the term "and / or" throughout the text includes three solutions. Taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies both A and B. In addition, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] Example 1

[0031] S1. Take heavy calcium carbonate, modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140°C to obtain foamed surface layer mixture; take modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140°C to obtain foamed bottom layer mixture.

[0032] S2. When the foamed surface layer mixture and the foamed bottom layer mixture from step S1 are cooled to 60°C, the foamed surface layer mixture is fed to a twin-screw extruder, and the foamed bottom layer mixture is fed to a single-screw extruder.

[0033] S3. The foamed surface layer mixture and the foamed bottom layer mixture are extruded separately using a screw extruder. Foaming agents for the foamed surface layer and the foamed bottom layer are added separately during extrusion. The extrusion temperature of the screw extruder is set as follows: Zone 1 260℃, Zone 2 275℃, Zone 3 270℃, Zone 4 265℃, Zone 5 265℃, Zone 6 265℃, Connector 265℃, Die Head Zone 265℃.

[0034] S4. The extruded foamed surface layer mixture and foamed bottom layer mixture are adjusted for flow rate and thickness using a melt pump and distributor, with a flow rate of 2500 cm³ for both. 2 / min, the thickness of the foamed surface layer is 4mm, and the thickness of the foamed bottom layer is 0.4mm; then it enters the mold for in-mold compounding and extrusion molding;

[0035] S5. After extrusion in step S4, the foamed surface layer and the foamed bottom layer become one; at the same time, a colored wear-resistant layer is bonded to the surface of the foamed surface layer, and after cooling, it is cut to obtain the foamed floor.

[0036] The preparation methods of foamed flooring in Examples 2 to 8 are the same as those in Example 1. The amount of raw materials and reaction conditions in Examples 1 to 8 are shown in Tables 1 and 2.

[0037] Table 1. Amounts of each raw material used in each embodiment (by weight).

[0038]

[0039]

[0040] The monomer ratio in the ethylene-methyl acrylate-glycidyl methacrylate copolymer is 10:40:50; the ratio of methyl acrylate to glycidyl acrylate in the methyl acrylate-glycidyl methacrylate difunctionalized ethylene elastomer is 30:70; and the monomer ratio in the styrene-methyl methacrylate-glycidyl methacrylate copolymer is 10:40:50.

[0041] Table 2 Reaction conditions for each step in each embodiment.

[0042]

[0043]

[0044] The properties of the flooring prepared in Examples 1 to 8 are shown in Table 3.

[0045] Table 3 shows the performance of the flooring prepared in each example.

[0046]

[0047] The difference between Comparative Example 1 and Example 1 is that the raw materials of the foamed top layer and the foamed bottom layer do not contain acrylate-glycidyl ester bifunctionalized vinyl elastomers.

[0048] The difference between Comparative Example 2 and Example 1 is that the raw materials of the foamed top layer and the foamed bottom layer do not contain ethylene-methyl acrylate-glycidyl methacrylate copolymer.

[0049] The difference between Comparative Example 3 and Example 1 is that the raw materials of the foamed top layer and the foamed bottom layer do not contain styrene-methyl methacrylate-glycidyl methacrylate copolymer.

[0050] The difference between Comparative Example 4 and Example 1 is that, in the raw materials of the foamed top layer and the foamed bottom layer, an equal amount of styrene-methyl methacrylate-glycidyl methacrylate copolymer was replaced with an equal amount of pyromellitic anhydride.

[0051] The difference between Comparative Example 5 and Example 1 is that the foamed flooring only contains a foamed surface layer.

[0052] The properties of the flooring prepared in Comparative Examples 1-5 are shown in Table 4.

[0053] Table 4 shows the performance of the flooring prepared in Comparative Examples 1-5.

[0054] Test Plan Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 <![CDATA[Specific gravity (g / cm 3 )]]> 1.4 1.5 1.4 1.6 1.3 Shrinkage / % (80℃ 6H) 0.25 0.32 0.14 0.5 1.5 Warpage / mm (80℃ 6H) 1.5 1.3 1.25 0.35 2.1 Tensile strength / MPa 1.5 1.4 1.2 2.2 1.6 Elongation at break / % 35 33 34 42 42 Water bath warpage / mm (60℃ 168H) 0.25 0.33 0.42 0.25 1.6 Shrinkage / % (0℃ 6H) 0.15 0.15 0.16 0.21 0.52 Warpage / mm (0℃ 6H) 1.5 1.3 1.2 0.4 1.7 Water bath warpage / mm (0℃ 168H) 0.16 0.25 0.30 0.17 0.41

[0055] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A foamed floor panel, characterized in that, The product comprises a foamed top layer and a foamed bottom layer. The foamed top layer, by weight, comprises the following raw materials: 70-90 parts PET resin, 20-30 parts heavy calcium carbonate, 12-20 parts modifier, 10-16 parts chain extender, 2-10 parts foaming agent, 0.5-3 parts internal lubricant, and 0.5-3 parts external lubricant. The foamed bottom layer, by weight, comprises the following raw materials: 30-40 parts PET resin, 6-10 parts modifier, 2-8 parts chain extender, 1-5 parts foaming agent, 0.5-3 parts internal lubricant, and 0.5-3 parts external lubricant.

2. The foamed flooring according to claim 1, characterized in that: The modifier is a mixture of acrylate-glycidyl acrylate bifunctionalized ethylene elastomer and ethylene-methyl acrylate-glycidyl methacrylate copolymer.

3. A foamed flooring according to claim 2, characterized in that: The mass ratio of the ethylene-methyl acrylate-glycidyl methacrylate copolymer to the acrylate-glycidyl acrylate difunctionalized ethylene elastomer is (6-8):(1-2).

4. A foamed flooring according to claim 1, characterized in that: The chain extender includes at least one of ethylenediamine polyether tetraol, polyoxypropylene triol, and styrene-methyl methacrylate-glycidyl methacrylate copolymer.

5. A foamed flooring according to claim 1, characterized in that: The foaming agent includes any one of azodicarbonamide, carbon dioxide, and cyclopentane.

6. A foamed flooring according to claim 1, characterized in that: The internal lubricant includes any one of stearic acid and siloxane.

7. A foamed flooring according to claim 1, characterized in that: The external lubricant includes PE wax.

8. A foamed flooring according to claim 1, characterized in that: The surface of the foamed layer is also covered with a colored wear-resistant layer.

9. A method for preparing foamed flooring as described in any one of claims 1-8, characterized in that: S1. Take heavy calcium carbonate, modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140-150℃ to obtain foamed surface layer mixture; take modifier, chain extender, PET resin, internal lubricant, and external lubricant, mix and stir, and heat to 140-150℃ to obtain foamed bottom layer mixture. S2. When the foamed surface layer mixture and the foamed bottom layer mixture from step S1 are cooled to 60-70°C, they are respectively fed to a screw extruder. S3. The foamed surface layer mixture and the foamed bottom layer mixture are extruded separately using a screw extruder. Foaming agents for the foamed surface layer and the foamed bottom layer are added separately during extrusion. The extrusion temperature of the screw extruder is set as follows: Zone 1 260~270℃, Zone 2 275~290℃, Zone 3 270~280℃, Zone 4 255~265℃, Zone 5 255~265℃, Zone 6 255~265℃, Connector 255~265℃, Die Head Zone 255~265℃. S4. The extruded foamed surface layer mixture and foamed bottom layer mixture are adjusted in flow rate and thickness by melt pump and distributor, and then enter the mold for in-mold compounding and extrusion molding. S5. After extrusion in step S4, the foamed surface layer and the foamed bottom layer become one piece; at the same time, a colored wear-resistant layer is bonded to the surface of the foamed surface layer, and after cooling, it is cut to obtain the foamed floor.

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