PVC plastic particles used for outdoor furniture and preparation method thereof

Abstract

The present application relates to the field of polymer materials, and more specifically, it relates to a PVC plastic pellet used for outdoor furniture and a preparation method thereof. It is composed of the following raw materials in parts by weight: 45-50 parts of PVC resin powder, 22-27 parts of plasticizer, 18-27 parts of filler, 1-3 parts of flame retardant, 3-6 parts of stabilizer, 0.8-1.2 parts of lubricant, 0.5-1 parts of colorant, and 0.4-8 parts of anti-aging agent; the anti-aging agent is composed of at least two of hindered phenolic antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano titanium dioxide. By using an anti-aging agent composed of at least two of hindered phenolic antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano titanium dioxide, and in combination with plasticizers, fillers, and other additives, the obtained PVC plastic pellets have both better mechanical properties and anti-aging properties, reduce the aging discoloration, brittleness, cracking, etc. of outdoor furniture made of PVC plastic pellets after long-term use, so that it maintains better mechanical properties and improves durability.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and more specifically, to PVC plastic particles used in outdoor furniture and a preparation method thereof. Background Art

[0002] Outdoor furniture refers to a series of utensils, relative to indoor furniture, that are set up in open or semi-open outdoor spaces to facilitate people's healthy, comfortable and efficient public outdoor activities. It mainly covers four major categories of products: urban public outdoor furniture, courtyard outdoor leisure furniture, commercial outdoor furniture, and portable outdoor furniture.

[0003] For example, rest tables, chairs, umbrellas, etc. used in outdoor or semi-outdoor spaces; with the scarcity of wood resources, more and more imitation wood products are also widely used, such as plastic wood, plastic wood, PVC, PS modified materials, etc.; and PVC has excellent plasticity, processing performance, low cost, corrosion resistance, safety, environmental protection, recyclability and other advantages, so it is widely used in outdoor furniture.

[0004] However, the outdoor furniture currently made of PVC is subject to long-term wind, sun and rain during use, which accelerates the aging of the PVC outdoor furniture, causing it to be easily damaged, discolored, cracked, etc., affecting the appearance and physical properties of the PVC outdoor furniture. Summary of the invention

[0005] In order to obtain better anti-aging properties and mechanical properties and improve the durability of PVC outdoor furniture, the present application provides a PVC plastic pellet used for outdoor furniture and a preparation method thereof.

[0006] In a first aspect, the present application provides a PVC plastic pellet for outdoor furniture, which is composed of the following raw materials in parts by weight:

[0007] PVC resin powder 45-50 parts

[0008] Plasticizer 22-27 parts

[0009] Filling 18-27 parts

[0010] Processing aids 5.3-11.2 parts

[0011] Anti-aging agent 0.4-8 parts;

[0012] The anti-aging agent consists of at least two of hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives and nano titanium dioxide.

[0013] In the above technical solution, hindered phenol antioxidants are a type of phenolic compounds with a spatially hindered structure, which are environmentally friendly, non-toxic, have good compatibility, low volatility, good thermal stability, and high antioxidant efficiency; hydroxytyrosol derivatives have good antioxidant properties, UV resistance, and compatibility, and hydroxytyrosol can effectively absorb ultraviolet radiation and reduce aging of PVC. Rosin derivatives have the characteristics of rosin resin, so they have the characteristics of environmental protection, thermal stability, antioxidant properties, UV resistance, etc.; titanium dioxide has good antioxidant properties and can absorb ultraviolet rays to play an anti-ultraviolet role.

[0014] When at least two of hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives and nano titanium dioxide are compounded, a synergistic anti-aging effect is achieved, so that the obtained anti-aging agent can be used in PVC plastic particles to achieve better anti-aging properties.

[0015] Furthermore, when the hindered phenolic antioxidant and the hydroxytyrosol derivative are compounded, the weight portion of the antioxidant is preferably 0.4-1.3 parts; the weight ratio of the hindered phenolic antioxidant and the hydroxytyrosol derivative is preferably (1-5):(3-8).

[0016] When the hydroxytyrosol derivative and the rosin derivative are compounded, the weight portion of the anti-aging agent is preferably 0.8-5 parts; the weight ratio of the hydroxytyrosol derivative to the rosin derivative is (0.5-1):(0.3-4).

[0017] When hydroxytyrosol derivatives, rosin derivatives and nano-titanium dioxide are compounded, the weight portion of the anti-aging agent is preferably 2-10 parts, and the weight ratio of the hydroxytyrosol derivatives, rosin derivatives and nano-titanium dioxide is (0.3-0.8): (0.5-2.2): (1.2-7).

[0018] In summary, the present application adopts an anti-aging agent composed of at least two of hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide, which has better antioxidant and anti-ultraviolet effects, and is combined with plasticizers, fillers, and processing aids to fully and evenly mix the raw material system of PVC plastic particles, and make the obtained PVC plastic particles have both better mechanical properties and aging resistance, reduce the possibility of aging, discoloration, brittleness, cracking, and breakage of outdoor furniture made of PVC plastic particles after long-term use, so that it maintains better mechanical properties and improves the durability of PVC outdoor furniture.

[0019] Hydroxytyrosol grafted onto chitosan is prepared by adding a catalyst to the activated hydroxytyrosol and chitosan solution and controlling the reaction temperature, time, pH value and other conditions to allow the hydroxyl groups of the activated hydroxytyrosol to undergo a grafting reaction with the amino groups on the chitosan chain. The grafting rate refers to the proportion of hydroxytyrosol successfully grafted onto the chitosan molecular chain.

[0020] Hydroxytyrosol grafted chitosan has the properties of both hydroxytyrosol and chitosan, making it more resistant to oxidation and UV rays, and further improving the anti-aging properties of PVC plastic particles.

[0021] Preferably, the weight ratio of the hindered phenol antioxidant, the hydroxytyrosol derivative, the rosin derivative and the nano-titanium dioxide is 1:(2-4):(3-8):(4-13).

[0022] When hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide are used to compound and form an anti-aging agent, a better anti-aging synergistic effect is achieved, so that the antioxidant and UV resistance of the anti-aging agent are better, thereby making the outdoor furniture produced by PVC plastic particles have better anti-aging properties, reducing the possibility of breakage, discoloration, and damage of outdoor furniture made of PVC plastic particles after long-term use, and improving the durability of PVC outdoor furniture.

[0023] Preferably, the hindered phenol antioxidant is 2,6-tert-butyl-4-methylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0024] 2,6-tert-butyl-4-methylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) both have good antioxidant effects, and are combined with one or more of hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide to obtain an antioxidant with good anti-aging performance, thereby reducing the possibility of aging, discoloration, brittleness, cracking, and breakage of PVC plastic particles after being used in outdoor furniture, thereby improving the durability and aesthetics of PVC outdoor furniture.

[0025] Preferably, the hydroxytyrosol derivative is one or more of hydroxytyrosol alkyl ether compounds, hydroxytyrosol oleate, and hydroxytyrosol grafted chitosan.

[0026] Hydroxytyrosol alkyl ether compounds, hydroxytyrosol oleate, and hydroxytyrosol grafted chitosan all have good antioxidant and UV resistance, and are combined with hindered phenol antioxidants, hydroxytyrosol derivatives, and nano-titanium dioxide to obtain an antioxidant with good anti-aging performance, which reduces the possibility of aging, discoloration, brittleness, cracking, and breakage of PVC plastic particles after being used in outdoor furniture, thereby improving the durability and aesthetics of PVC outdoor furniture.

[0027] When hydroxytyrosol alkyl ether compounds, hydroxytyrosol oleate, and hydroxytyrosol grafted chitosan are compounded, a synergistic effect is exerted to further improve the anti-aging properties of PVC plastic particles.

[0028] Preferably, the rosin derivative is one or more of maleic rosin and / or rosin-modified maleic acid resin.

[0029] Maleic rosin and rosin-modified maleic acid resin both have the antioxidant and UV resistance of rosin, and have better compatibility, thereby improving the compatibility of the principle system of PVC plastic particles, thereby making the mechanical properties and anti-aging properties of PVC plastic particles better, so that outdoor furniture produced from PVC plastic particles has better durability and color retention.

[0030] Preferably, the filler is a modified filler, and the modified filler is composed of the following raw materials in parts by weight: 0.1-0.3 parts of 2-carboxybenzotriazole

[0031] 1-5 parts of silicone acrylate

[0032] Initiator 0.05-0.08 parts

[0033] Solvent 10-20 parts

[0034] 20-30 portions of filler.

[0035] The solvent includes water and anhydrous ethanol, and the weight ratio of water to anhydrous ethanol is 3:7.

[0036] Preparation method of modified filler:

[0037] According to the weight percentage, the initiator is weighed and dissolved in water to obtain a mixture A; then 2-carboxybenzotriazole, siloxy acrylate and anhydrous ethanol are weighed, mixed evenly, added to the mixture A, heated to 60-70°C, stirred for 1-2h, adjusted the pH value to 7-7.5, and then the filler is added, mixed evenly, filtered, and the filter residue is dried to obtain a modified filler.

[0038] In the above technical solution, the siloxy acrylate is γ-methacryloxypropyl trimethoxysilane, and 2-carboxybenzotriazole is also called 2-hydroxy-5-methyl-1,2,3-benzotriazole, which has a light stabilizer to prevent degradation caused by ultraviolet rays. γ-methacryloxypropyl trimethoxysilane and 2-carboxybenzotriazole are compounded to form a composite polymer, and after neutralization, the raw material system is neutralized, and fillers are added to make the composite polymer easily form a stable coating film on the surface of the filler, thereby improving the compatibility of the modified filler with the PVC plastic particle raw material system, and further improving the UV resistance and mechanical properties of the PVC plastic particles, so that it can obtain better anti-aging agents and mechanical properties.

[0039] Preferably, the plasticizer is epoxidized soybean oil and / or trioctyl trimellitate.

[0040] Epoxidized soybean oil and trioctyl trimellitate both have better plasticizing effects; when epoxy soybean oil and trioctyl trimellitate are compounded, they have better plasticizing effects, thereby making the performance of PVC plastic particles better.

[0041] Preferably, the filler is one or more of heavy calcium carbonate, light calcium carbonate and kaolin.

[0042] Heavy calcium carbonate, light calcium carbonate and kaolin all have the function of filling and toughening, which can further enhance the mechanical properties of PVC.

[0043] Preferably, the processing aid is composed of the following raw materials in parts by weight:

[0044] Flame retardant 1-3 parts

[0045] 3-6 parts of stabilizer

[0046] Lubricant 0.8-1.2 parts

[0047] Colorant 0.5-1 part.

[0048] The flame retardant is antimony trioxide; the stabilizer is calcium zinc stabilizer; and the lubricant is PE wax and / or oxidized polyethylene wax.

[0049] Antimony trioxide is used as a flame retardant with better flame retardant effect, calcium zinc stabilizer has better thermal stability, PE wax and oxidized polyethylene wax both play a lubricating role and assist processing. Therefore, the above materials are combined with anti-aging agents, plasticizers, and fillers to make the obtained PVC plastic particles have better performance.

[0050] In a second aspect, the present application provides a method for preparing PVC plastic pellets for outdoor furniture, comprising the following steps:

[0051] PVC resin powder, plasticizer, filler, processing aid and anti-aging agent are weighed and mixed evenly according to weight parts, melt-extruded, cooled and granulated to obtain PVC plastic granules.

[0052] The above raw materials are mixed to make them fully mixed and then melt extruded to make the materials compatible again, so that the obtained VC plastic particles have better performance.

[0053] In summary, this application has the following beneficial effects:

[0054] 1. The present application adopts an anti-aging agent composed of at least two of hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide, which has better antioxidant and anti-ultraviolet effects, and is combined with plasticizers, fillers, and processing aids to fully mix the raw material system of PVC plastic particles, and make the obtained PVC plastic particles have both better mechanical properties and aging resistance, reduce the aging, discoloration, brittleness, etc. of PVC outdoor furniture made of PVC plastic particles after long-term use, so that it maintains better mechanical properties and improves durability.

[0055] 2. A composite polymer is formed by compounding γ-methacryloxypropyltrimethoxysilane and 2-carboxybenzotriazole. After neutralization, the raw material system is neutralized. Fillers are added to make the composite polymer easily form a stable coating film on the surface of the fillers, thereby improving the compatibility of the modified fillers with the PVC plastic particle raw material system, and further improving the UV resistance of the PVC plastic particles, so that a better anti-aging agent is obtained. DETAILED DESCRIPTION

[0056] The present application is further described in detail below with reference to the embodiments.

[0057] Introduction table of some raw materials;

[0058] Table 1 Introduction of some raw materials

[0059]

[0060]

[0061] Example

[0062] Example 1

[0063] A PVC plastic pellet used for outdoor furniture is prepared by the following method:

[0064] Weigh 45kg PVC resin powder, 22kg plasticizer, 10kg heavy calcium carbonate, 5kg light calcium carbonate, 3kg kaolin, 1kg antimony trioxide, 3kg calcium zinc stabilizer, 0.8kg lubricant, 0.5kg colorant, 0.1kg hindered phenol antioxidant, and 0.3kg hydroxytyrosol derivative into a high-speed mixer, stir for 5min at a speed of 150r / min to fully mix the materials, transfer to a twin-screw extruder for melt extrusion at a screw speed of 400 rpm, cool in a cold water tank, and then enter a 100°C oven for drying for 10s, and enter a granulator for granulation to obtain PVC plastic particles.

[0065] The hindered phenol antioxidant is composed of 2,6-tert-butyl-4-methylphenol; the hydroxytyrosol derivative is composed of hydroxytyrosol alkyl ether compounds.

[0066] Table 2 Temperature settings of twin-screw extruder

[0067] Temperature ℃ Zone 1 Zone 2 Zone 3 District 4 District 5 District 6 District 7 Die head set up 150 155 160 165 165 158 155 155 actual 147 153 158 162 163 155 152 153

[0068] Example 2-11

[0069] The difference between Example 2-11 and Example 1 is that the composition and amount of raw materials are different, as shown in Table 3 and Table 4;

[0070] Table 3 Composition of raw materials and dosage of raw materials in Examples 1-6 (kg)

[0071]

[0072] Table 4 Composition of raw materials and dosage of raw materials in Examples 7-11 (kg)

[0073]

[0074] Example 12

[0075] The difference between Example 12 and Example 10 is that the anti-aging agent consists of 0.5 kg of hindered phenol antioxidant, 1 kg of hydroxytyrosol derivative, 1.5 kg of rosin derivative, and 2 kg of nano titanium dioxide.

[0076] Embodiment 13

[0077] The difference between Example 13 and Example 10 is that the anti-aging agent consists of 0.3 kg of hindered phenol antioxidant, 0.7 kg of hydroxytyrosol derivative, 1.2 kg of rosin derivative, and 2.8 kg of nano titanium dioxide.

[0078] Embodiment 14

[0079] The difference between Example 14 and Example 10 is that the anti-aging agent consists of 0.2 kg of hindered phenol antioxidant, 0.8 kg of hydroxytyrosol derivative, 1.5 kg of rosin derivative, and 2.5 kg of nano titanium dioxide.

[0080] Embodiment 15

[0081] The difference between Example 15 and Example 13 is that the hindered phenol antioxidant is composed of 0.1 kg 2,6-tert-butyl-4-methylphenol and 0.2 kg 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0082] Example 16

[0083] The difference between Example 16 and Example 15 is that the hydroxytyrosol derivative consists of 0.2 kg of hydroxytyrosol alkyl ether compound, 0.1 kg of hydroxytyrosol oleate, and 0.4 kg of hydroxytyrosol grafted chitosan.

[0084] Embodiment 17

[0085] The difference between Example 17 and Example 16 is that the rosin derivative consists of 0.5 kg of maleic rosin and 0.7 kg of rosin-modified maleic acid resin.

[0086] Embodiment 18

[0087] The difference between Example 18 and Example 17 is that the filler is a modified filler. The preparation method of the modified filler is as follows: 0.05 kg of ammonium persulfate is weighed and dissolved in 4.5 kg of water to obtain a mixture A; then 0.1 kg of 2-carboxybenzotriazole, 1 kg of siloxyacrylate and 7 kg of anhydrous ethanol are weighed and put into a reactor and mixed evenly, added to the mixture A, heated to 68°C, stirred at a speed of 100 r / min for 2 hours, and then the pH value in the reactor is adjusted to 7, and then 20 kg of filler (the weight ratio of heavy calcium carbonate, light calcium carbonate and kaolin is 11:7:4) is added, and stirring is continued for 30 minutes. Filter using a filtering device, and then the filter residue is placed in an oven at 100°C for drying for 4 hours to obtain a modified filler.

[0088] The siloxy acrylate is gamma-methacryloxypropyltrimethoxysilane.

[0089] Embodiment 19

[0090] The difference between Example 19 and Example 18 is that the preparation method of the modified filler is:

[0091] 0.07 kg of ammonium persulfate was weighed and dissolved in 6.5 kg of water to obtain a mixture A; 0.2 kg of 2-carboxybenzotriazole, 3 kg of siloxyacrylate and 9.5 kg of anhydrous ethanol were weighed and put into a reactor and mixed evenly, and then added to the mixture A, heated to 68 ° C, stirred at a speed of 100 r / min for 2 hours, and then the pH value in the reactor was adjusted to 7, and then 25 kg of filler (the weight ratio of heavy calcium carbonate, light calcium carbonate and kaolin is 11:7:4) was added, and stirring was continued for 30 minutes. The filter was filtered using a filtering device, and the filter residue was placed in an oven at 100 ° C for 4 hours to obtain a modified filler.

[0092] Embodiment 20

[0093] The difference between Example 20 and Example 18 is that the preparation method of the modified filler is:

[0094] Weigh 0.08 kg of ammonium persulfate and dissolve it in 6 kg of water to obtain a mixture A; then weigh 0.3 kg of 2-carboxybenzotriazole, 5 kg of siloxyacrylate and 14 kg of anhydrous ethanol, put them into a reactor and mix them evenly, add them into the mixture A, heat to 68 ° C, stir at a speed of 100 r / min for 2 hours, then adjust the pH value in the reactor to 7, and then add 30 kg of filler (the weight ratio of heavy calcium carbonate, light calcium carbonate and kaolin is 11:7:4), continue stirring for 30 minutes, filter using a filtering device, and then put the filter residue into a 100 ° C oven for drying for 4 hours to obtain a modified filler.

[0095] Embodiment 21

[0096] The difference between Example 21 and Example 18 is that 2-carboxybenzotriazole is replaced by siloxy acrylate in equal amounts.

[0097] Comparative Example

[0098] Comparative Example 1

[0099] The difference between Comparative Example 1 and Example 1 is that the anti-aging agent is 2,6-tert-butyl-4-methylphenol.

[0100] Comparative Example 2

[0101] The difference between Comparative Example 2 and Example 1 is that the anti-aging agent is a hydroxytyrosol alkyl ether compound.

[0102] Comparative Example 3

[0103] The difference between Comparative Example 3 and Example 1 is that the anti-aging agent is maleic rosin.

[0104] Comparative Example 4

[0105] The difference between Comparative Example 4 and Example 1 is that the anti-aging agent is nano titanium dioxide.

[0106] Comparative Example 5

[0107] The difference between Comparative Example 5 and Example 1 is that pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is replaced by 2,6-tert-butyl-4-methylphenol in an equal amount.

[0108] Comparative Example 6

[0109] The difference between Comparative Example 6 and Example 1 is that, based on Comparative Example 5, the amount of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate used is 1 kg.

[0110] Performance testing

[0111] Detection method / test method

[0112] The PVC plastic pellets obtained in Examples 1-21 and Comparative Examples 1-6 were injection molded to obtain test samples and the following experiments were performed:

[0113] 1. Take 5 test samples from each group to test the tensile strength and elongation at break. The test standard refers to GB / T2951.1-1997.

[0114] 2. Take 5 test samples from each group for aging treatment

[0115] Each cycle is 8 hours, for a total of 24 cycles;

[0116] Among them, ultraviolet irradiation for 4 hours (lamp UVA-340nm, power 0.63W / (m 2 nm) and temperature is 60°C), 4 hours of humidity (temperature is 50°C, ambient humidity is 85%), each cycle test is continued until the test is completed; and then the test is performed as shown in Table 5.

[0117] Table 5 Experimental data of Examples 1-23 and Comparative Examples 1-6

[0118]

[0119]

[0120] Combining Example 1 and Comparative Examples 1-5 and Table 5, it can be seen that the residual elongation at break and the residual tensile strength of Comparative Examples 1-4 are lower than those of Example 1, indicating that the use of at least two of the hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide in the present application to form an anti-aging agent has a better antioxidant effect, reduces the possibility of aging, discoloration, brittleness, and breakage of PVC plastic particles, and has better durability when used for outdoor furniture.

[0121] Combining Example 1 and Comparative Example 6 with Table 5, it can be seen that the elongation at break and the tensile strength of Comparative Example 6 are lower than those of Example 1, indicating that the PVC plastic particles obtained by using the raw material composition and dosage ratio of the present application have better mechanical properties.

[0122] Combining Example 2 and Example 10 and Table 5, it can be seen that the elongation at break, tensile strength, residual elongation at break, and residual tensile strength of Example 2 are all lower than those of Example 10, indicating that the use of hindered phenol antioxidants, hydroxytyrosol derivatives, rosin derivatives, and nano-titanium dioxide plays a synergistic role, making the anti-aging performance and mechanical properties of PVC plastic particles better.

[0123] Combining Example 17 and Example 18 and Table 5, it can be seen that the elongation at break, tensile strength, residual elongation at break, and residual tensile strength of Example 17 are all lower than those of Example 18, indicating that the modified filler obtained by the preparation method of the present application can interact with the anti-aging agent, thereby making the VC plastic particles have better anti-aging properties and mechanical properties.

[0124] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A PVC plastic pellet used for outdoor furniture, characterized in that: It is composed of the following raw materials in parts by weight: PVC resin powder 45-50 parts Plasticizer 22-27 parts Filling 18-27 parts Processing aids 5.3-11.2 parts Anti-aging agent 0.4-8 parts; The anti-aging agent is composed of a hindered phenol antioxidant, a hydroxytyrosol derivative, a rosin derivative and nano titanium dioxide in a weight ratio of 1: (2-4): (3-8): (4-13).

2. The PVC plastic pellets for outdoor furniture according to claim 1, characterized in that: The hindered phenol antioxidant is 2,6-tert-butyl-4-methylphenol and / or 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

3. The PVC plastic pellets for outdoor furniture according to claim 1, characterized in that: The hydroxytyrosol derivative is one or more of hydroxytyrosol alkyl ether compounds, hydroxytyrosol oleate, and hydroxytyrosol grafted chitosan.

4. The PVC plastic pellets for outdoor furniture according to claim 1, characterized in that: The rosin derivative is one or more of maleic rosin and / or rosin-modified maleic acid resin.

5. The PVC plastic pellets for outdoor furniture according to claim 1, characterized in that: The filler is a modified filler, and the modified filler is composed of the following raw materials in parts by weight: 2-Carboxybenzotriazole 0.1-0.3 parts 1-5 parts of silicone acrylate Initiator 0.05-0.08 parts 10-20 parts of diluent 20-30 portions of filler.

6. The PVC plastic pellets for outdoor furniture according to claim 1, characterized in that: The plasticizer is epoxidized soybean oil and / or trioctyl trimellitate.

7. The PVC plastic pellets used for outdoor furniture according to claim 1, characterized in that: The filler is one or more of heavy calcium carbonate, light calcium carbonate and kaolin.

8. The PVC plastic pellets used for outdoor furniture according to claim 1, characterized in that: The processing aid is composed of the following raw materials in parts by weight: Flame retardant 1-3 parts 3-6 parts of stabilizer Lubricant 0.8-1.2 parts Colorant 0.5-1 part.

9. A method for preparing PVC plastic particles for outdoor furniture according to any one of claims 1 to 8, characterized in that: The following steps are involved: PVC resin powder, plasticizer, filler, processing aid and anti-aging agent are weighed and mixed evenly according to weight parts, melt-extruded, cooled and granulated to obtain PVC plastic granules.

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