Needle-shaped filling high-stability PVC floor and preparation method thereof

Abstract

The invention discloses a needle-shaped filling high-stability PVC floor and a preparation method thereof. The needle-shaped filling high-stability PVC floor comprises the following components in parts by mass: 53-56 parts of PVC resin powder, 10-20 parts of magnesium sulfate whiskers, 19-22 parts of a plasticizer, 3-4 parts of a lubricant, 1-2 parts of a first processing aid and 1-2 parts of a second processing aid. The PVC floor contains the magnesium sulfate whiskers, so that the magnesium sulfate whiskers can reinforce, toughen and disperse the impact force on the material and prevent the expansion of cracks, thereby enhancing the bending strength and impact resistance of the PVC floor.

Description

Technical Field

[0001] The invention relates to the technical field of floor materials, and in particular to a needle-filled high-stability PVC floor and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a non-toxic and harmless renewable resource made by the polymerization of vinyl chloride monomer. It has excellent chemical stability, insulation and flame retardancy. At the same time, it is widely used in the flooring industry because of its low price and wide availability of raw materials. Polyvinyl chloride (PVC) flooring has the disadvantages of fragile surface, hard texture, easy decomposition of HCl pollutant gas, and decomposition temperature close to plasticizing temperature, resulting in poor impact resistance and thermal stability. Therefore, we use needle-shaped inorganic fillers to fill modified PVC to improve the impact resistance and thermal stability of PVC composite materials.

[0003] Defects and shortcomings of the prior art: Due to its low price, calcium carbonate is often used as a filler in PVC flooring. Calcium carbonate is a hydrophilic inorganic compound with a large number of hydroxyl structures on its surface, which makes it have poor affinity with organic polymers and easily forms aggregates. It is unevenly dispersed inside the polymer, thus causing interface defects between composite materials. This uneven dispersion may lead to a decrease in the impact resistance and thermal stability of PVC materials. At the same time, during high-temperature processing, calcium carbonate will decompose and release carbon dioxide gas, causing bubbles to form inside the PVC material, which will also affect the impact resistance and thermal stability of PVC flooring, hindering the widespread application of PVC flooring. Summary of the invention

[0004] In order to solve the above technical problems, the PVC floor of the present invention contains magnesium sulfate whiskers, which can reinforce and toughen, disperse the impact force on the material, prevent the expansion of cracks, and thus improve the bending strength and impact resistance of the PVC floor.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is: the present invention provides a needle-filled high-stability PVC floor, comprising the following components in parts by mass: 53-56 parts of PVC resin powder, 10-20 parts of magnesium sulfate whiskers, 15-20 parts of chopped glass fibers, 19-22 parts of plasticizer, 3-4 parts of lubricant, 1-2 parts of a first processing aid and 1-2 parts of a second processing aid.

[0006] Furthermore, the plasticizer is dioctyl terephthalate.

[0007] Furthermore, the lubricant is a mixture of calcium stearate and zinc stearate in a mass ratio of 5:4.

[0008] Furthermore, the first processing aid is MBS (methyl methacrylate-butadiene-styrene copolymer).

[0009] Furthermore, the second processing aid is MC (chlorinated polyethylene).

[0010] Furthermore, the fiber diameter of the chopped glass fibers is 6-13 μm, and the moisture content is ≤0.1%.

[0011] The present invention also provides a method for preparing the needle-filled high-stability PVC floor, comprising the following steps:

[0012] Step 1. After weighing the raw materials according to a certain mass ratio, first add the PVC resin, magnesium sulfate whisker and chopped glass fiber into a high-speed mixer and mix them thoroughly for 10-15 minutes, then add the plasticizer, lubricant, the first processing aid and the second processing aid into the mixer, stir them thoroughly for 10-15 minutes, wait for the material temperature to rise to about 140-160°C, cool it, and obtain a mixed powder for preparing the PVC floor;

[0013] Step 2. The mixed powder cooled in step 1 is extruded and granulated by a twin-screw extruder to obtain a PVC floor modified material;

[0014] Step 3. Add the modified PVC floor material obtained in step 2 into an injection molding machine to injection mold the floor.

[0015] The beneficial effects of the present invention are:

[0016] Magnesium sulfate whiskers are added to the PVC floor of the present invention. Magnesium sulfate whiskers are a kind of white needle-shaped single crystal fibers with the characteristics of high strength and high modulus. It has good compatibility with plastics, so the composite material exhibits excellent physical and mechanical properties. When used in the PVC floor of the present invention, magnesium sulfate whiskers can reinforce and toughen, disperse the impact force on the material, prevent the expansion of cracks, and thus improve the bending strength and impact resistance of the PVC floor. Therefore, when magnesium sulfate whiskers are used as fillers, their needle-shaped fiber structure can be evenly dispersed in the PVC matrix, thereby improving the mechanical strength of the PVC floor. The addition of magnesium sulfate whiskers has basically no effect on the Vicat softening temperature of the PVC floor, indicating that it has little effect on thermal stability. In addition, during high-temperature processing, the final decomposition products of magnesium sulfate whiskers are non-toxic, which can inhibit the generation of droplets in the combustion process of the PVC floor and increase the amount of carbonization, thereby improving the flame retardant properties of the floor;

[0017] The PVC floor of the present invention adds an appropriate amount of short-cut glass fibers to replace lignin fibers and polyester fibers, thereby solving the problem that the wood-plastic floor is easy to absorb water and expand and deform. The short-cut glass fibers have excellent fluidity in wet dispersion and are easily impregnated with resin when preparing flame-retardant materials, thereby ultimately enhancing the mechanical strength and plasticity of the flame-retardant materials.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0019] The following is a specific embodiment of the present invention, and those skilled in the art can easily understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented in other different ways, that is, different modifications and changes can be made without departing from the scope disclosed by the present invention.

[0020] Example 1: A needle-filled high-stability PVC floor is prepared according to the following method, which comprises the following steps:

[0021] Step 1. After weighing the raw materials according to a certain mass ratio, first add 53 parts of PVC resin, 10 parts of magnesium sulfate whiskers and 15 parts of chopped glass fibers into a high-speed mixer and mix them thoroughly for 10-15 minutes, then add 19 parts of plasticizer, 3 parts of lubricant, 1 part of the first processing aid and 1 part of the second processing aid into the mixer, stir thoroughly for 10-15 minutes, wait for the material temperature to rise to about 150°C, cool it, and obtain a mixed powder for preparing PVC flooring.

[0022] Step 2. Add the cooled mixed powder in step 1 into the twin-screw extruder, and set the temperature from the feeding port to the die of the twin-screw extruder to four sections, which are set to 160°C, 170°C, 180°C, and 185°C respectively, for melt blending and extrusion.

[0023] Step 3. After extrusion, granulation and cooling, the needle-shaped filled high-stability PVC floor substrate is obtained

[0024] Step 4. Add the needle-shaped filled high-stability PVC floor substrate obtained in step 3 into an injection molding machine for injection molding into a high-stability PVC floor.

[0025] Example 2: The steps are the same as those of Example 1, except that the amount of PVC resin is changed to 54 parts, the amount of magnesium sulfate whiskers is changed to 15 parts, the amount of chopped glass fibers is changed to 16 parts, the amount of plasticizer is changed to 22 parts, the amount of lubricant is changed to 4 parts, the amount of the first processing aid is changed to 2 parts, and the amount of the second processing aid is changed to 2 parts.

[0026] Example 3: The steps are the same as those of Example 1, except that the amount of PVC resin is changed to 55 parts, the amount of magnesium sulfate whiskers is changed to 20 parts, the amount of chopped glass fibers is changed to 17 parts, the amount of plasticizer is changed to 20 parts, the amount of lubricant is changed to 3.5 parts, the amount of the first processing aid is changed to 1 part, and the amount of the second processing aid is changed to 1 part.

[0027] Example 4: The steps are the same as those of Example 1, except that the amount of PVC resin is changed to 56 parts, the amount of magnesium sulfate whiskers is changed to 12 parts, the amount of chopped glass fibers is changed to 18 parts, the amount of plasticizer is changed to 21 parts, the amount of lubricant is changed to 4 parts, the amount of the first processing aid is changed to 1 part, and the amount of the second processing aid is changed to 2 parts.

[0028] Example 5: The steps are the same as those of Example 1, except that the amount of PVC resin is changed to 53 parts, the amount of magnesium sulfate whiskers is changed to 18 parts, the amount of chopped glass fibers is changed to 20 parts, the amount of plasticizer is changed to 19 parts, the amount of lubricant is changed to 3 parts, the amount of the first processing aid is changed to 2 parts, and the amount of the second processing aid is changed to 1 part.

[0029] Comparative Example 1: A conventional PVC floor is prepared according to the following method, which comprises the following steps:

[0030] Step 1. After weighing the raw materials according to a certain mass ratio, first add 53 parts of PVC resin and 10 parts of calcium carbonate into a high-speed mixer and mix them thoroughly for 10-15 minutes, then add the plasticizer, lubricant, the first processing aid and the second processing aid into the mixer, stir them thoroughly for 10-15 minutes, wait for the material temperature to rise to about 150°C, cool it, and obtain a mixed powder for preparing the PVC floor; wherein the plasticizer, lubricant, the first processing aid and the second processing aid are the same as those in Example 1.

[0031] Step 2. Add the cooled mixed powder in step 1 into the twin-screw extruder, and set the temperature from the feeding port to the die of the twin-screw extruder to four sections, which are set to 160°C, 170°C, 180°C, and 185°C respectively, for melt blending and extrusion.

[0032] Step 3. After extrusion, granulation and cooling, the PVC floor substrate is obtained.

[0033] Step 4. Add the PVC floor substrate obtained in step 3 into an injection molding machine for injection molding into a PVC floor.

[0034] Performance evaluation method and implementation standard: After the materials prepared in the above embodiments and comparative examples are dried, they are added to an injection molding machine for injection molding into test specimens. The limiting oxygen index is tested according to the GB / T 2406.2-2009 standard. The limiting oxygen index (LOl) refers to the minimum oxygen concentration required for the material to burn in a mixed gas of oxygen and nitrogen under specified conditions. It is generally expressed as the volume percentage of oxygen. The higher the LOl of the measured material, the better its flame retardant performance; the tensile strength is measured according to the GB / T6344-2008 standard. The tensile strength refers to the maximum tensile force that the measured material is subjected to when it breaks in a tensile test. However, the greater the tensile strength, the more brittle the material is, and the worse its impact strength will be. The impact strength is tested according to the GB-T 1843-2008 standard. The impact strength refers to the resistance of the material when it is subjected to an impact load. The higher the impact strength of the measured material, the better its impact resistance and toughness. The thermal properties are tested according to the ASTM F1514 mark. The thermal properties are mainly heat resistance temperature and low temperature resistance temperature. The heat resistance temperature usually refers to its Vicat softening temperature. If the temperature exceeds this temperature, the material will deform or soften. The results of the above tests are shown in Table 1.

[0035] From the performance test results of Examples 1-5 and Comparative Example 1, it can be seen that the limiting oxygen index and impact strength of the composite materials made of PVC materials modified with magnesium sulfate whiskers (Examples 1-5) are higher than those of the PVC composite materials modified with calcium carbonate (Comparative Example 1), which shows that the addition of magnesium sulfate whiskers improves the flame retardancy, toughness and thermal deformation capacity of the polyvinyl chloride material, which indicates that the composite materials made of polyvinyl chloride modified with magnesium sulfate whiskers have good flame retardancy, toughness and thermal stability.

[0036] Table 1

[0037] project Limiting oxygen index (%) <![CDATA[Impact strength (kJ / m 2 )]]> Tensile strength(MPa) Heat deformation temperature(℃) Example 1 31 10.2 17.1 88.2 Example 2 32 9.8 18.8 90.5 Example 3 35 8.7 22.4 95.0 Example 4 31 11.0 16.8 89.0 Example 5 33 10.5 19.1 92.1 Comparative Example 1 28 7.1 24.0 75.9

[0038] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A needle-filled high-stability PVC floor, characterized by: The invention comprises the following components in parts by mass: 53-56 parts of PVC resin powder, 10-20 parts of magnesium sulfate whisker, 15-20 parts of chopped glass fiber, 19-22 parts of plasticizer, 3-4 parts of lubricant, 1-2 parts of the first processing aid and 1-2 parts of the second processing aid.

2. The needle-filled high-stability PVC floor according to claim 1, characterized in that: The plasticizer is dioctyl terephthalate.

3. The needle-filled high-stability PVC floor according to claim 1, characterized in that: The lubricant is a mixture of calcium stearate and zinc stearate in a mass ratio of 5:

4.

4. The needle-filled high-stability PVC floor according to claim 1, characterized in that: The first processing aid is MBS.

5. The needle-filled high-stability PVC floor according to claim 1, characterized in that: The second processing aid is MC.

6. The needle-filled high-stability PVC floor according to claim 1, characterized in that: The fiber diameter of the chopped glass fibers is 6-13 μm, and the moisture content is ≤0.1%.

7. A method for preparing the needle-filled high-stability PVC floor according to claim 1, characterized in that: The steps include: Step 1. After weighing the raw materials according to a certain mass ratio, first add the PVC resin, magnesium sulfate whisker and chopped glass fiber into a high-speed mixer and mix them thoroughly for 10-15 minutes, then add the plasticizer, lubricant, the first processing aid and the second processing aid into the mixer, stir them thoroughly for 10-15 minutes, wait for the material temperature to rise to about 140-160°C, cool it, and obtain a mixed powder for preparing the PVC floor; Step 2. The mixed powder cooled in step 1 is extruded and granulated by a twin-screw extruder to obtain a PVC floor modified material; Step 3. Add the modified PVC floor material obtained in step 2 into an injection molding machine to injection mold the floor.