High-stability PVC wood-plastic material and preparation method thereof

Abstract

The invention provides a high-stability PVC wood-plastic material and a preparation method thereof, and relates to the technical field of wood-plastic composites.The high-stability PVC wood-plastic material is prepared from, by weight, 80-100 parts of PVC resin, 20-30 parts of wood flour, 15-30 parts of calcium carbonate, 8-15 parts of stabilization assisting material, 4-8 parts of stabilizer, 1-6 parts of foaming agent, 1-2 parts of coupling agent, 5-10 parts of processing aid and 1-4 parts of lubricant; the stabilizing material comprises beta-diketone, a phosphite ester compound and a light stabilizer. According to the invention, the stabilizing material is added into the formula system of the PVC wood-plastic material, so that the processing stability and tolerance of the PVC wood-plastic material are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of wood-plastic composite materials, and in particular to a high-stability PVC wood-plastic material and a preparation method thereof. Background Art

[0002] Wood-plastic composite materials are a new type of reversible and recyclable multi-purpose material that is made of renewable biomass resources such as woody / grass / vine plants and their processing residues as the main raw materials, mixed with a certain proportion of high-molecular polymer base materials and inorganic fillers, and processed by special additives through high-tech means such as physics, chemistry and bioengineering, and processed through special processes. PVC wood-plastic material is the main type of wood-plastic composite material, that is, a composite material formed by melt blending of polyvinyl chloride (PVC) and plant fiber materials (usually wood powder). It is green and environmentally friendly and has the excellent properties of both wood and plastic.

[0003] Although PVC wood-plastic materials have outstanding advantages such as waterproof and moisture-proof, anti-corrosion and anti-insect, and excellent mechanical properties, during the PVC processing process, since the molecular structure of PVC wood-plastic materials contains double bonds and branched structures remaining in the polymerization reaction, these structures are easily degraded under the action of heat and light, releasing hydrogen chloride, resulting in a decrease in the processing stability of the material and poor weather resistance and other resistance of the material.

[0004] Based on this, the present invention discloses a high-stability PVC wood-plastic material and a preparation method thereof, wherein the material not only has excellent processing stability but also has outstanding weather resistance and other properties. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a highly stable PVC wood-plastic material and a preparation method thereof, which solves the problems of insufficient processing stability and poor weather resistance during use of the prior PVC wood-plastic material.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] The highly stable PVC wood-plastic material comprises the following materials in parts by weight: 80-100 parts of PVC resin, 20-30 parts of wood powder, 15-30 parts of calcium carbonate, 8-15 parts of stabilizing materials, 4-8 parts of stabilizers, 1-6 parts of foaming agents, 1-2 parts of coupling agents, 5-10 parts of processing aids, and 1-4 parts of lubricants; the stabilizing materials comprise β-diketone, phosphite compounds, and light stabilizers.

[0010] Preferably, the mass ratio of the β-diketone, the phosphite compound and the light stabilizer is 1:(2-4):(0.1-0.3).

[0011] Preferably, the phosphite compound comprises triethyl triphenyl phosphate, tris(2,4-dichlorophenoxy)phosphate and isopropyl triphenyl phosphate in a mass ratio of 1:(1.7-2.4):(0.8-1.2).

[0012] Preferably, the light stabilizer includes light stabilizer HPT, ascorbyl palmitate, light stabilizer 770, and AM-101 in a mass ratio of 1: (0.7-1.3): (2-2.5): (0.3-0.6).

[0013] Preferably, it also includes 5-10 parts of maleic anhydride grafted polyethylene or maleic anhydride grafted polyvinyl chloride.

[0014] Preferably, the stabilizer is a mixture of calcium stearate, zinc stearate and magnesium stearate.

[0015] Preferably, the blowing agent is azodicarbonamide.

[0016] Preferably, the coupling agent is titanate or aluminate.

[0017] Preferably, the lubricant is paraffin or silicone oil.

[0018] The preparation method of high-stable PVC wood-plastic material specifically comprises the following steps:

[0019] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder and calcium carbonate, and mix the above components evenly;

[0020] The stabilizing material and the stabilizer are mixed evenly separately, and then the mixture is added to the above mixed system, and finally a foaming agent, a coupling agent, a processing aid, and a lubricant are added to the mixed system, and stirred to react;

[0021] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain a finished product.

[0022] (III) Beneficial effects

[0023] The present invention provides a highly stable PVC wood-plastic material and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention adds stabilizing materials to the PVC wood-plastic material formula system. The stabilizing materials are mainly β-diketone, phosphite compounds, and light stabilizers. Both β-diketone and phosphite compounds are heat stabilizers. The two have synergistic effects, and the light stabilizer has an auxiliary effect, which effectively improves the processing stability and durability of the PVC wood-plastic material.

[0025] 2. Secondly, the stabilizing materials and stabilizers have a synergistic effect, which further improves the processing stability and durability of PVC wood-plastic materials. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The embodiments of the present application provide a highly stable PVC wood-plastic material and a preparation method thereof, thereby solving the problems of insufficient processing stability and poor weather resistance of existing PVC wood-plastic materials during use.

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0029] The raw materials used in the present invention are all purchased from cooperative manufacturers.

[0030] Embodiment 1:

[0031] Highly stable PVC wood-plastic material, including the following materials in parts by weight:

[0032]

[0033]

[0034] The preparation method of high-stable PVC wood-plastic material specifically comprises the following steps:

[0035] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder and calcium carbonate, and mix the above components evenly;

[0036] The stabilizing material and the stabilizer are mixed separately and evenly, and then the mixture is added to the above mixed system, and finally azodicarbonamide, titanate and paraffin are added to the mixed system, and stirred to react;

[0037] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain a finished product.

[0038] Embodiment 2:

[0039] Highly stable PVC wood-plastic material, including the following materials in parts by weight:

[0040]

[0041]

[0042] The preparation method of high-stable PVC wood-plastic material specifically comprises the following steps:

[0043] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder and calcium carbonate, and mix the above components evenly;

[0044] The stabilizing material and the stabilizer are mixed separately and evenly, and then the mixture is added to the above mixed system, and finally azodicarbonamide, aluminate and silicone oil are added to the mixed system, and stirred to react;

[0045] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain a finished product.

[0046] Example 3

[0047] Highly stable PVC wood-plastic material, including the following materials in parts by weight:

[0048]

[0049]

[0050] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder and calcium carbonate, and mix the above components evenly;

[0051] The stabilizing material and the stabilizer are mixed separately and evenly, and then the mixture is added to the above mixed system, and finally azodicarbonamide, titanate and silicone oil are added to the mixed system, and stirred to react;

[0052] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain a finished product.

[0053] Embodiment 4 is different from Embodiment 2 in that:

[0054] The PVC wood-plastic material system also includes 5 parts of maleic anhydride grafted polyethylene.

[0055] Embodiment 5 is different from Embodiment 2 in that:

[0056] The PVC wood-plastic material system also includes 10 parts of maleic anhydride grafted polyethylene.

[0057] Embodiment 6 is different from Embodiment 2 in that:

[0058] The PVC wood-plastic material system also includes 5 parts of maleic anhydride grafted polyvinyl chloride.

[0059] Embodiment 7 is different from Embodiment 2 in that:

[0060] The PVC wood-plastic material system also includes 10 parts of maleic anhydride grafted polyvinyl chloride.

[0061] Comparative Example 1 is different from Example 2 in that:

[0062] No stabilizing materials are added to the system.

[0063] Comparative Example 2 is different from Example 2 in that:

[0064] Delete β-diketone from the stabilizing material.

[0065] Comparative Example 3 is different from Example 2 in that:

[0066] Remove phosphite compounds from stabilizing materials.

[0067] Comparative Example 4 is different from Example 2 in that:

[0068] Delete the light stabilizer in the stabilizing material.

[0069] Comparative Example 5 is different from Example 2 in that:

[0070] The β-diketone in the stabilizing material is replaced by an organic tin stabilizer.

[0071] Comparative Example 6 is different from Example 2 in that:

[0072] In the stabilizing material, the mass ratio of β-diketone, phosphite compound and light stabilizer is 1:5:0.5.

[0073] Comparative Example 7 is different from Example 2 in that:

[0074] In the stabilizing material, the mass ratio of β-diketone, phosphite compound and light stabilizer is 1:1:0.05.

[0075] Comparative Example 8 is different from Example 2 in that:

[0076] Delete triethyl triphenyl phosphate from the phosphite compounds.

[0077] Comparative Example 9 is different from Example 2 in that:

[0078] Delete triethyl triphenyl phosphate and tris(2,4-dichlorophenoxy)phosphate from the phosphite compounds.

[0079] Comparative Example 10 is different from Example 2 in that:

[0080] The tris(2,4-dichlorophenoxy)phosphate in the phosphite compound is replaced by triphenyl phosphite.

[0081] Comparative Example 11 is different from Example 2 in that:

[0082] The tris(2,4-dichlorophenoxy)phosphate and triphenyl isopropyl phosphate in the phosphite compounds are replaced by triphenyl phosphite and polyethylene glycol di(2-methylpropylene glycol) phosphate, respectively.

[0083] Comparative Example 12 is different from Example 2 in that:

[0084] The mass ratio of triethyl triphenyl phosphate, tri(2,4-dichlorophenoxy) phosphate and isopropyl triphenyl phosphate in the phosphite compounds is 1:2.6:1.5.

[0085] Comparative Example 13 is different from Example 2 in that:

[0086] The mass ratio of triethyl triphenyl phosphate, tri(2,4-dichlorophenoxy) phosphate and isopropyl triphenyl phosphate in the phosphite compounds is 1:1.5:0.6.

[0087] Comparative Example 14 is different from Example 2 in that:

[0088] Delete light stabilizer HPT and light stabilizer 770 from the light stabilizer.

[0089] Comparative Example 15 is different from Example 2 in that:

[0090] Delete ascorbyl palmitate from the light stabilizer.

[0091] Comparative Example 16 is different from Example 2 in that:

[0092] The light stabilizer HPT in the light stabilizer is replaced by light stabilizer 292.

[0093] Comparative Example 17 is different from Example 2 in that:

[0094] Replace light stabilizer 770 with light stabilizer 292 in the light stabilizer.

[0095] Comparative Example 18 is different from Example 2 in that:

[0096] The light stabilizer HPT and light stabilizer 770 in the light stabilizer were replaced with light stabilizer 292 and light stabilizer 944 respectively.

[0097] Comparative Example 19 is different from Example 2 in that:

[0098] Delete AM-101 in the light stabilizer.

[0099] Comparative Example 20 is different from Example 3 in that:

[0100] The mass ratio of the light stabilizer HPT, ascorbyl palmitate, light stabilizer 770, and AM-101 in the light stabilizer is 1:1.5:2.5:0.6.

[0101] Comparative Example 21 is different from Example 1 in that:

[0102] The mass ratio of the light stabilizer HPT, ascorbyl palmitate, light stabilizer 770, and AM-101 in the light stabilizer is 1:0.5:2:0.3.

[0103] Comparative Example 22 is different from Example 2 in that:

[0104] Delete the magnesium stearate component in the stabilizer.

[0105] Comparative Example 23 is different from Example 2 in that:

[0106] Delete the calcium stearate component in the stabilizer.

[0107] Comparative Example 24 is different from Example 2 in that:

[0108] Delete the magnesium stearate and zinc stearate components in the stabilizer.

[0109] Comparative Example 25 is different from Example 2 in that:

[0110] The zinc stearate in the stabilizer was replaced by barium stearate.

[0111] Performance test data

[0112] The high heat-resistant PVC wood-plastic composite materials prepared by the methods of Examples 1-7 and Comparative Examples 1-25 and the preparation methods thereof were sampled, and the following performance tests were performed on each group of samples:

[0113] 1. Impact strength

[0114] According to GB / T 1843-2008 "Determination of Izod Impact Strength of Plastics", the sample size is 80mm×10mm×4mm, 6 samples are tested and the average value is taken.

[0115] 2. Heat deformation temperature

[0116] Tested according to IS075-2-2013 standard, the test pressure is 1.82MPa;

[0117] 3. High temperature tensile performance retention rate

[0118] According to ISO 527-2-2012 standard, the initial tensile strength of the sample at room temperature was tested (tensile rate 50mm / min), and then the sample was subjected to high temperature treatment at a temperature of 120°C for a test time of 2000h. If powdering occurred during the test, it was recorded as "powdering". If powdering did not occur, the high temperature treated sample was tested for aging tensile strength according to the above method after the temperature dropped to room temperature. The retention rate was recorded statistically. If it exceeded 100%, it was uniformly recorded as ">100%", where the retention rate was greater than 100%, indicating that the material performance did not significantly decay after aging, and the material had excellent heat resistance. The calculation formula for the high temperature tensile performance retention rate is: (tensile strength after aging / initial tensile strength) × 100%.

[0119] 4. Weather resistance

[0120] Tested according to ISO 4892-3.

[0121] The observation data under the UV aging test is used to characterize the weather resistance of the sample. Specifically, by simulating the ultraviolet radiation in sunlight, the cracking and fading of the sample under long-term exposure are observed.

[0122] Table 1- Performance test data of samples

[0123]

[0124]

[0125] From the data in Table 1, we can see that:

[0126] 1. The experimental data of the samples of Examples 1-3 show that the samples prepared by the technical solution of the present invention have excellent processing stability and heat resistance, weather resistance and other resistances.

[0127] 2. The experimental data of the samples of Examples 1-7 show that, on the basis of adding the stabilizing material, adding maleic anhydride grafted polyethylene or maleic anhydride grafted polyvinyl chloride to the system is beneficial to further improve the impact strength, stability and durability of the sample. This is because the stabilizing material of the technical solution of the present invention includes multiple components, which may have problems of poor compatibility or dispersibility when added to the system. Adding maleic anhydride grafted polyethylene or maleic anhydride grafted polyvinyl chloride can improve this defect and effectively improve the compatibility of the PVC wood-plastic material system and the dispersibility of each component.

[0128] 3. The experimental data of the samples of Example 2 and Comparative Examples 1-5 show that the stabilizing material in the technical solution of the present invention has obvious stabilizing and durability enhancing effects, and there is a synergistic effect between the three components of β-diketone, phosphite compound and light stabilizer. Regardless of deleting one of the components or replacing it with other components with similar effects, the technical effect brought about by the joint action of the above three components cannot be achieved.

[0129] 4. The experimental data of the samples of Example 2 and Comparative Examples 6-7 show that the ratio of the three components of β-diketone, phosphite compound and light stabilizer will also affect the overall stability of the system. Therefore, the ratio needs to be controlled within an appropriate range to fully exert the effectiveness of the synergistic components.

[0130] 5. The phosphite compounds in the technical solution of the present invention are selected from three components: triphenyl triethyl phosphate, tri(2,4-dichlorophenoxy) phosphate, and triphenyl isopropyl phosphate. Triphenyl triethyl phosphate mainly affects the colorability of the material, can keep the material transparent and colorless, and has strong thermal stability and oxidation stability. However, triphenyl triethyl phosphate has limited improvement on the weather resistance and fluidity of the PVC wood-plastic material system; tri(2,4-dichlorophenoxy) phosphate mainly affects the chemical stability processing performance, transparency and electrical properties of the material, can effectively prevent PVC from decomposing during processing, and at the same time make up for the limited defects of triphenyl triethyl phosphate in improving the weather resistance of the material, and enhance the weather resistance and cold resistance of the material; triphenyl isopropyl phosphate mainly affects the water absorption, aging and fading problems of the product, and it has excellent antioxidant properties. According to the sample experimental data of Example 2 and Comparative Examples 8-11, it can be proved that these three components have a synergistic effect, and the synergistic effect decreases when these three components are replaced.

[0131] 6. The experimental data of the samples of Example 2 and Comparative Examples 12-13 show that the ratio of the three components of triethyl triphenyl phosphate, tri(2,4-dichlorophenoxy) phosphate and isopropyl triphenyl phosphate will also affect the overall stability of the system. Therefore, the ratio needs to be controlled within an appropriate range to fully exert the effectiveness of the synergistic components.

[0132] 7. The light stabilizers in the technical solution of the present invention are selected from light stabilizer HPT, ascorbyl palmitate, light stabilizer 770, and AM-101. Ascorbyl palmitate has a natural antioxidant effect, and AM-101, as a nickel-based quencher, has the effect of enhancing the synergy of the light stabilizer. In addition, the nickel ions in AM-101 can produce a certain synergistic catalytic effect with β-diketone, which has a synergistic effect on improving the stability of the system. According to the sample experimental data of Example 2 and Comparative Examples 14-19, there is a synergistic effect between light stabilizer HPT, ascorbyl palmitate, light stabilizer 770, and AM-101. If one of the four components is replaced, the synergistic effect will decrease.

[0133] 8. The experimental data of the samples of Example 2 and Comparative Examples 20-21 show that the ratio of the four components, namely, photostabilizer HPT, ascorbyl palmitate, photostabilizer 770 and AM-101, will also affect the overall stability of the system. Therefore, the ratio needs to be controlled within an appropriate range to fully exert the effectiveness of the synergistic components.

[0134] 9. The stabilizer in the technical solution of the present invention is a mixture of calcium stearate, magnesium stearate and zinc stearate. Zinc stearate has excellent lubricity, low anti-mixing torque value and slow gelation speed; calcium stearate and magnesium stearate have good gelation performance and high anti-mixing torque value. The three components work together to improve the defects of each component, and since the three components are all metal soaps, they can enhance the efficacy of β-diketone. According to the sample experimental data of Example 2 and Comparative Examples 22-24, it can be proved that the three components have a synergistic effect.

[0135] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0136] 1. The present invention adds stabilizing materials to the PVC wood-plastic material formula system. The stabilizing materials are mainly β-diketone, phosphite compounds, and light stabilizers. Both β-diketone and phosphite compounds are heat stabilizers. The two have synergistic effects, and the light stabilizer has an auxiliary effect, which effectively improves the processing stability and durability of the PVC wood-plastic material.

[0137] 2. Secondly, there is a synergistic effect between the stabilizing material and the stabilizer. Calcium stearate, magnesium stearate and zinc stearate are all metal soaps, which can enhance the efficacy of β-diketone, which is beneficial to further improve the processing stability and durability of PVC wood-plastic materials.

[0138] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0139] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly stable PVC wood-plastic material, characterized in that: The invention comprises the following materials in parts by weight: 80-100 parts of PVC resin, 20-30 parts of wood flour, 15-30 parts of calcium carbonate, 8-15 parts of stabilizing materials, 4-8 parts of stabilizers, 1-6 parts of foaming agents, 1-2 parts of coupling agents, 5-10 parts of processing aids and 1-4 parts of lubricants; the stabilizing materials comprise β-diketone, phosphite compounds and light stabilizers.

2. The high-stability PVC wood-plastic material according to claim 1, characterized in that: The mass ratio of the β-diketone, the phosphite compound and the light stabilizer is 1:(2-4):(0.1-0.3).

3. The high-stability PVC wood-plastic material according to claim 2, characterized in that: The phosphite compound comprises triethyl triphenyl phosphate, tris(2,4-dichlorophenoxy)phosphate and isopropyl triphenyl phosphate in a mass ratio of 1:(1.7-2.4):(0.8-1.2).

4. The high-stability PVC wood-plastic material according to claim 2, characterized in that: The light stabilizer includes light stabilizer HPT, ascorbyl palmitate, light stabilizer 770 and AM-101 in a mass ratio of 1: (0.7-1.3): (2-2.5): (0.3-0.6).

5. The high-stability PVC wood-plastic material according to claim 1, characterized in that: It also includes 5-10 parts of maleic anhydride grafted polyethylene or maleic anhydride grafted polyvinyl chloride.

6. The high-stability PVC wood-plastic material according to claim 1, characterized in that: The stabilizer is a mixture of calcium stearate, zinc stearate and magnesium stearate.

7. The high-stability PVC wood-plastic material according to claim 1, characterized in that: The foaming agent is azodicarbonamide.

8. The high-stability PVC wood-plastic material according to claim 1, characterized in that: The coupling agent is titanate or aluminate.

9. The high-stability PVC wood-plastic material according to claim 1, characterized in that: The lubricant is paraffin or silicone oil.

10. The method for preparing the high-stable PVC wood-plastic material according to any one of claims 1 to 9, characterized in that: The specific steps include: First, heat the PVC resin to a molten state, stir it evenly, then add wood powder and calcium carbonate, and mix the above components evenly; The stabilizing material and the stabilizer are mixed evenly separately, and then the mixture is added to the above mixed system, and finally a foaming agent, a coupling agent, a processing aid, and a lubricant are added to the mixed system, and stirred to react; After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

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