Foamed spc stone plastic floor and preparation method thereof

Abstract

The application discloses a foamed SPC stone plastic floor and a preparation method thereof, and relates to the technical field of multilayer structure SPC stone plastic floors. The foamed SPC stone plastic floor comprises a three-layer structure which is sequentially composed of an ultraviolet-resistant scratch-resistant layer, a foamed buffer layer and a base material layer from top to bottom; the ultraviolet-resistant scratch-resistant layer is composed of an ultraviolet-resistant scratch-resistant material; the ultraviolet-resistant scratch-resistant material comprises the following components and mass fractions: 80-120 parts of polyvinyl chloride, 10-30 parts of nano silicon dioxide, 1-5 parts of an ultraviolet absorber, 0.5-3 parts of a light stabilizer, 5-20 parts of a scratch-resistant auxiliary agent and 5-40 parts of pigments. The foamed SPC stone plastic floor of the application synergizes the components of specific ultraviolet absorbers and light stabilizers, can effectively block ultraviolet rays, reduces the performance degradation of the material caused by light, and significantly enhances the ultraviolet aging resistance compared with the prior art, so that the problems of obvious discoloration, color change and the decrease of strength and toughness caused by molecular chain rupture of the floor during long-term use can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of multi-layer SPC stone plastic flooring technology, specifically to a foamed SPC stone plastic flooring and its preparation method. Background Technology

[0002] In the use of stone-plastic composite (SPC) flooring, resistance to ultraviolet (UV) aging is crucial. High-energy UV rays can break the chemical bonds within the material, triggering photochemical reactions and leading to material degradation. Traditional SPC flooring often uses organic polymers such as polyvinyl chloride (PVC), which, while possessing some mechanical strength, lack sufficient resistance to UV aging. Under prolonged exposure to sunlight, SPC flooring will fade and discolor; for example, white flooring will gradually turn yellow, and colored flooring will lighten in color. This not only affects the aesthetics of the flooring but may also indicate changes in the internal properties of the material. In terms of physical properties, UV radiation breaks polymer molecular chains, damaging the internal structure of the material, reducing the flooring's strength and toughness, making it prone to cracking, warping, and other problems, thus shortening its lifespan.

[0003] While existing technologies incorporate anti-aging additives into stone-plastic composite (SPC) flooring, their effectiveness is limited. Insufficient UV-resistant additives fail to effectively block ultraviolet rays, while excessive additives degrade material processing performance and increase costs. Furthermore, poor compatibility between additives and the matrix material can lead to migration and precipitation, reducing the durability of UV aging resistance. Therefore, developing novel foamed SPC flooring and its preparation methods is crucial to addressing these issues. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a foamed SPC stone plastic flooring with excellent anti-ultraviolet aging properties and its preparation method. Through a three-layer structure design and optimized material combination, it effectively blocks ultraviolet rays, enhances scratch resistance, significantly improves the service life and performance of the flooring, and meets market demands.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a foamed SPC stone plastic flooring, comprising a three-layer structure layered from top to bottom: an anti-UV and scratch-resistant layer, a foamed buffer layer, and a substrate layer;

[0006] The UV-resistant and scratch-resistant layer is made of UV-resistant and scratch-resistant material;

[0007] The UV-resistant and scratch-resistant material comprises the following components and their weight percentages: 80-120 parts polyvinyl chloride, 10-30 parts nano silica, 1-5 parts UV absorber, 0.5-3 parts light stabilizer, 5-20 parts scratch-resistant additive, and 5-40 parts pigment.

[0008] The ultraviolet absorber is a compound represented by Formula 1:

[0009] Formula 1;

[0010] In Formula 1, R1 is selected from: methyl, ethyl, propyl.

[0011] Furthermore, the particle size of the nano-silica is 50-100 nm.

[0012] Furthermore, the pigment is selected from: stone-like coatings.

[0013] Furthermore, the ultraviolet absorber is any one of the compounds shown in the following structures:

[0014] ;

[0015] .

[0016] Furthermore, the light stabilizer is selected from: light stabilizer 770, the CAS number of light stabilizer 770 is: 52829-07-9.

[0017] Furthermore, the scratch-resistant additive is selected from titanium dioxide.

[0018] Furthermore, the foamed buffer layer is composed of polyvinyl chloride foam material.

[0019] Furthermore, the substrate layer is made of cork.

[0020] A method for preparing foamed SPC stone plastic flooring includes the following steps:

[0021] S1. Preparation of UV-resistant and scratch-resistant layer: The polyvinyl chloride, nano silica, UV absorber, light stabilizer, scratch-resistant additive and pigment are mixed in parts by mass, stirred and extruded into a sheet to obtain UV-resistant and scratch-resistant layer;

[0022] S2. Preparation of foamed buffer layer: The polyvinyl chloride foaming material is added to a foaming agent and extruded and foamed through a twin-screw extruder, with the foaming ratio controlled at 1.5-3.0 times, to obtain a foamed buffer layer;

[0023] S3. Preparation of substrate layer: Cut the cork into boards of predetermined thickness to obtain the substrate layer;

[0024] S4. Composite: The UV-resistant and scratch-resistant layer, the foamed buffer layer and the substrate layer are stacked from top to bottom and fed into a hot press. They are then composited and cured under temperature and pressure. After cooling, they are cut to obtain a foamed SPC stone plastic floor.

[0025] Furthermore, the foaming agent is sodium bicarbonate.

[0026] Furthermore, the hot pressing conditions of the S4 hot press are: temperature 150-180℃, pressure 8-15MPa, and holding time 5-10 minutes.

[0027] Furthermore, the stirring temperature in S1 is 80-120℃, and the stirring time is 10-30 minutes.

[0028] Furthermore, the extrusion molding temperature in S1 is 140-170℃.

[0029] In the structure of the UV absorber described in this invention, the presence of conjugated large π bonds and cyano groups enables its highly efficient UV absorption function. The molecular skeleton of the UV absorber contains an extended conjugated π-electron system, which significantly reduces the molecule's electronic transition energy levels (HOMO-LUMO band), causing a redshift in its absorption spectrum and efficiently covering the UVA (320-400 nm) and UVB (280-320 nm) bands. When the conjugated system absorbs UV photons, electrons transition from the ground state to the excited singlet state, releasing energy as molecular vibrational energy (thermal energy), thus protecting the material. The linear structure of the cyano group is perpendicular to the benzene ring plane, increasing steric hindrance and reducing the attack of oxygen molecules on active sites. The cyano group lowers the highest occupied orbital (HOMO) energy, making it less susceptible to oxidation and preventing self-decomposition to generate free radicals. The electron-withdrawing property of the cyano group makes it easier for the UV absorber to transfer excited-state energy to the hindered amine photostable agent, which captures free radicals, forming a dual protection of "UV absorption-free radical quenching".

[0030] The components of polyvinyl chloride, nano-silica, ultraviolet absorber, light stabilizer, titanium dioxide, and pigments in the UV-resistant and scratch-resistant layer of this invention work synergistically, combined with a three-layer structure design and process control, to systematically solve the problem of UV aging in stone-plastic flooring. The specific mechanism is as follows: nano-silica, with its 50-100nm particle size matching the UV wavelength, forms a physical shield, synergistically constructing an inorganic particle reinforcement network with the high refractive index of titanium dioxide, improving Mohs hardness and UV scattering efficiency; the ultraviolet absorber absorbs UV photons and converts them into heat energy through the large π bonds of benzotriazole, and its cyano groups lower the HOMO energy level to enhance stability, forming an "absorption-quenching" dynamic cycle with the light stabilizer—the UV energy captured by the absorber is transferred to the hindered amine structure light stabilizer through intermolecular interactions, quenching free radicals and achieving a regeneration cycle. This functional layer, combined with the microporous secondary scattering and stress absorption of the foamed buffer layer, and the moisture barrier and elastic modulus matching of the cork substrate layer, constitutes a triple synergy of "protection-buffering-support".

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. Enhanced UV resistance: The foamed SPC stone plastic flooring of this invention uses a combination of specific UV absorbers and light stabilizers to effectively block ultraviolet rays and reduce the performance degradation of the material caused by light exposure. Compared with the prior art, its UV resistance is significantly enhanced, which can effectively avoid problems such as obvious fading, discoloration and decreased strength and toughness caused by molecular chain breakage during long-term use.

[0033] 2. Superior scratch resistance: By adding scratch-resistant additives to the UV-resistant scratch-resistant layer and optimizing the proportions of each component, the scratch resistance of the flooring of this invention is greatly improved. It can better resist scratches caused by sharp objects in daily use. Compared with the prior art, it has a greater advantage in maintaining aesthetics and effectively extends the service life of the flooring.

[0034] 3. Longer service life: Combining a three-layer structure design and material optimization, the flooring of this invention has excellent performance in terms of UV aging resistance, scratch resistance and stress cushioning. The overall service life is significantly extended compared with the existing technology, which can better meet the needs of long-term use and reduce the frequency of replacement and maintenance costs. Attached Figure Description

[0035] Figure 1 This is the NMR spectrum of the ultraviolet absorber 1 described in this invention. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Preparation Example 1

[0038] Synthesis of UV absorber 1:

[0039] ;

[0040] Under a nitrogen atmosphere, 20 g of starting material 1, 15.87 g of starting material 2, 16.24 g of potassium carbonate, 0.2 g of palladium on carbon, 0.77 g of triphenylphosphine, and 250 g of toluene were added to the reaction system. After stirring until homogeneous, the mixture was heated to 110 °C and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered using silica gel cake. 400 g of water was added to the organic phase, and the extraction was repeated three times. The organic phases were combined. The organic phase was dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness. Silica gel column chromatography was performed using a mixture of petroleum ether and ethyl acetate as eluent. After evaporation to dryness, 22.14 g of intermediate 1 was obtained.

[0041] Intermediate structure identification: Mass spectrometry (M / Z-MS+H) + ): 485.

[0042] ;

[0043] Under a nitrogen atmosphere, 22.14 g of intermediate 1, 15.08 g of starting material 3, 12.63 g of potassium carbonate, 0.16 g of palladium on carbon, 0.6 g of triphenylphosphine, and 250 g of toluene were added to the reaction system. After stirring until homogeneous, the mixture was heated to 110 °C and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered using silica gel cake. 300 g of water was added to the organic phase, and the extraction was repeated three times. The organic phases were combined. The organic phase was dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness. Silica gel column chromatography was performed using a mixture of petroleum ether and ethyl acetate as eluent. After evaporation to dryness, 25.01 g of ultraviolet absorber 1 was obtained.

[0044] Structural identification of UV absorber 1: Mass spectrometry (M / Z-MS+H) + ): 679.

[0045] The NMR spectra of UV absorber 1 are shown in [reference needed]. Figure 1 .

[0046] Preparation Example 2

[0047] The preparation of UV absorber 2 follows the same method as in Preparation Example 1, except that raw material 2 is replaced with... The rest remained the same as in Preparation Example 1. Structural identification of UV absorber 2: Mass spectrometry (M / Z-MS+H) + ): 693.

[0048] Preparation Example 3

[0049] The preparation of ultraviolet absorber 3 follows the same method as in Preparation Example 1, except that raw material 3 is replaced with... The rest remained the same as in Preparation Example 1. Structural identification of UV absorber 2: Mass spectrometry (M / Z-MS+H) + ): 707.

[0050] Example 1: Preparation of a foamed SPC stone plastic flooring:

[0051] 1. Raw material preparation:

[0052] The UV-resistant and scratch-resistant layer is a UV-resistant and scratch-resistant material containing the following components and their mass fractions: 100 parts of polyvinyl chloride, 20 parts of nano-silica (average particle size of 100 nm), 3 parts of UV absorber (UV absorber 1 prepared in Preparation Example 1), 1.5 parts of light stabilizer (light stabilizer 770), 10 parts of scratch-resistant additive (titanium dioxide), and 20 parts of pigment (imitation stone coating).

[0053] Foamed buffer layer: Polyvinyl chloride foam material, purchased from Jieyang Yijia Plastics Co., Ltd.;

[0054] Substrate layer: Cork.

[0055] 2. Preparation method:

[0056] S1. Preparation of UV-resistant and scratch-resistant layer: The above-mentioned polyvinyl chloride (100 parts), nano silica (20 parts), UV absorber 1 (3 parts), light stabilizer 770 (1.5 parts), titanium dioxide (10 parts), and pigment (20 parts) were added to a high-speed mixer according to their mass parts. The mixture was stirred at 150 rpm for 20 minutes at a stirring temperature of 100℃. The mixture was then fed into a single-screw extruder and extruded into a sheet at an extrusion temperature of 160℃, with a thickness controlled at 0.5 mm, to obtain the UV-resistant and scratch-resistant layer.

[0057] S2. Preparation of foamed buffer layer: Take polyvinyl chloride foam material, add foaming agent sodium bicarbonate (addition amount accounts for 5% of the mass of foam material), and extrude and foam through a twin-screw extruder (screw speed 150 rpm), control the foaming ratio to 2.0 times, and obtain a foamed buffer layer with a thickness of 2.0 mm.

[0058] S3. Substrate layer preparation: Cut the cork raw material into flat boards of a predetermined thickness (3.0mm), and sand the surface to enhance adhesion to obtain the substrate layer;

[0059] S4. Composite: The UV-resistant and scratch-resistant layer obtained in S1, the foamed buffer layer obtained in S2, and the substrate layer obtained in S3 are precisely stacked from top to bottom (total thickness approximately 5.5mm), and fed into a hot press. Under hot-pressing composite conditions: temperature 165℃, pressure 10MPa, holding time 7 minutes, after cooling to room temperature, it is cut into standard size (1200mm×200mm) to obtain a foamed SPC stone plastic flooring.

[0060] Examples 2-3: Preparation of foamed SPC stone plastic flooring, referring to the preparation method of Example 1, except that the ultraviolet absorber is replaced with ultraviolet absorber 2-ultraviolet absorber 3 prepared in Examples 2-3, and the rest is the same as in Example 1.

[0061] Comparative Example 1

[0062] The preparation of a foamed SPC stone plastic flooring is carried out according to the preparation method of Example 1, except that the ultraviolet absorber is replaced with comparative compound 1, and the rest is the same as in Example 1.

[0063] Comparative compound 1: Comparative compound 1 is UV-101, an ultraviolet absorber, with CAS number 57834-33-0.

[0064] Comparative Example 2

[0065] The preparation of a foamed SPC stone plastic flooring is carried out according to the preparation method of Example 1, except that the ultraviolet absorber is replaced with comparative compound 2, and the rest is the same as in Example 1.

[0066] Comparative compound 2: .

[0067] Comparative Example 3

[0068] The preparation of a foamed SPC stone plastic flooring is the same as in Example 1, except that the ultraviolet absorber is not added.

[0069] Comparative Example 4

[0070] The preparation of a foamed SPC stone plastic flooring is the same as in Example 1, except that no light stabilizer is added.

[0071] Comparative Example 5

[0072] The preparation of a foamed SPC stone plastic flooring is carried out by referring to the preparation method of Example 1, except that the mass part of the scratch-resistant additive is replaced with 1 part, and the rest is the same as in Example 1.

[0073] Performance testing:

[0074] 1. Mechanical property testing: Pencil hardness was tested according to GB / T 6739-2022 standard; impact performance was tested according to GB / T 1732-2020 standard, and the data are shown in Table 1.

[0075] 2. Weathering resistance test: The test was conducted according to the conditions specified in standard GB / T 1865-2009. During the test, the parameters such as the irradiance of the xenon arc lamp, the blackboard temperature, the relative humidity, and the water spray cycle of each sample were kept consistent to simulate the changes in light, temperature, and humidity in the natural environment. The test was conducted continuously for 2000 hours. The test specimens were then removed and the color change (ΔE / %) before and after aging was measured using a colorimeter. The experimental data are shown in Table 1. Then, the tested specimens were subjected to pencil hardness testing according to standard GB / T 6739-2022 and impact performance testing according to standard GB / T 1732-2020. The data are shown in Table 1.

[0076] Table 1.

[0077]

[0078] The example groups (Examples 1 to 3) using the specific UV absorber of this invention exhibited excellent overall performance. These examples demonstrated high levels of hardness and impact resistance even in their initial state, and after accelerated aging testing, their color stability was exceptionally good (minimal color change), while their mechanical properties were retained at a very high rate, demonstrating the material's durability and reliability in long-term use. In contrast, the comparative examples (Comparative Examples 1 to 5) showed a clear trend of performance degradation: when the UV absorber was replaced with the control compound or completely omitted, color changes were significantly aggravated (increased color difference), and the retention rate of hardness and impact resistance after aging decreased sharply, indicating that the absence or replacement of key components directly weakened the material's resistance to UV aging. Furthermore, the reduction in the amount of scratch-resistant additives also led to a slight decline in mechanical properties, but the core impact remained focused on the synergistic effect of the UV-protective components. Overall, this invention, through the optimized combination of UV absorbers and other components, significantly improved the weather resistance and structural stability of stone-plastic flooring.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A foamed SPC stone plastic floor, characterized in that, The three layers are sequentially compounded from top to bottom: an ultraviolet-resistant scratch-resistant layer, a foamed buffer layer and a substrate layer. The ultraviolet-resistant scratch-resistant layer is composed of an ultraviolet-resistant scratch-resistant material. The ultraviolet-resistant scratch-resistant material comprises the following components and mass fractions: polyvinyl chloride 80-120 parts, nano-silicon dioxide 10-30 parts, ultraviolet absorber 1-5 parts, light stabilizer 0.5-3 parts, scratch-resistant auxiliary agent 5-20 parts, and pigment 5-40 parts. The ultraviolet absorber is a compound represented by formula 1: Formula 1; R1 in formula 1 is selected from methyl, ethyl and propyl.

2. The foamed SPC stone plastic floor according to claim 1, characterized in that, The nano-silicon dioxide has a particle size of 50-100 nm.

3. The foamed SPC stone plastic floor according to claim 1, characterized in that, The ultraviolet absorber is any one of the compounds represented by the following structures: ； 。 4. The foamed SPC stone plastic floor according to claim 1, characterized in that, The light stabilizer is selected from light stabilizer 770, and the CAS number of light stabilizer 770 is 52829-07-9.

5. The foamed SPC stone plastic floor according to claim 1, characterized in that, The scratch-resistant auxiliary agent is selected from titanium dioxide.

6. The foamed SPC stone plastic floor according to claim 1, characterized in that, The foamed buffer layer is composed of polyvinyl chloride foaming material.

7. The foamed SPC stone plastic floor according to claim 1, characterized in that, The substrate layer is composed of softwood.

8. A method for preparing the foamed SPC stone plastic floor according to any one of claims 1-7, characterized in that, The method comprises the following steps: S1. Preparation of the ultraviolet-resistant scratch-resistant layer: the polyvinyl chloride, nano-silicon dioxide, ultraviolet absorber, light stabilizer, scratch-resistant auxiliary agent and pigment are mixed according to the mass fraction, and then extruded into a sheet after stirring to obtain the ultraviolet-resistant scratch-resistant layer; S2. Preparation of the foamed buffer layer: the polyvinyl chloride foaming material is added with a foaming agent, and then extruded and foamed by a double-screw extruder to control the foaming ratio to 1.5-3.0 times to obtain the foamed buffer layer; S3. Preparation of the substrate layer: the softwood is cut into a plate with a predetermined thickness to obtain the substrate layer; S4. Compounding: the ultraviolet-resistant scratch-resistant layer, foamed buffer layer and substrate layer are stacked from top to bottom and sent into a hot press for compounding and curing under temperature and pressure, and then cut after cooling to obtain a foamed SPC stone plastic floor.

9. The method for preparing foamed SPC stone plastic floor according to claim 8, characterized in that, The foaming agent is sodium bicarbonate.

10. The method for preparing foamed SPC stone plastic floor according to claim 8, characterized in that, The hot pressing and compounding conditions of the S4 hot press are: temperature 150-180℃, pressure 8-15MPa, and pressure maintaining time 5-10 minutes; The stirring temperature in S1 is 80-120℃, and the stirring time is 10-30 minutes; The extrusion molding temperature in S1 is 140-170℃.

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