Oil-separation-free high-flowability PVC material for toys and preparation method of oil-separation-free high-flowability PVC material

Abstract

The invention relates to the technical field of PVC toy processing, in particular to an oil-separation-free high-fluidity PVC material for toys and a preparation method thereof.The oil-separation-free high-fluidity PVC material is prepared from, by weight, 90-110 parts of PVC powder, 45-55 parts of calcium powder, 3-5 parts of a stabilizer, 0.8-1.2 parts of a lubricant and 80-100 parts of a plasticizer; according to the formula, the PVC material can effectively inhibit migration and precipitation of a plasticizer, the greasy and sticky phenomena on the surface of a toy are reduced, meanwhile, the high fluidity and good flexibility, tensile strength and impact resistance of the material are kept, and the PVC material is suitable for manufacturing soft toys needing flexibility and high fluidity.

Description

Technical Field

[0001] The present application relates to the technical field of PVC toy processing, and more specifically, to a high-fluidity PVC material for toys that does not exude oil and a preparation method thereof. Background Art

[0002] PVC has high tensile, bending, compressive and impact resistance capabilities and can withstand a certain amount of external force. By adding plasticizers, PVC can be made into soft or hard materials to meet the needs of different toys. Among them, in PVC soft toys, by adding a large amount of plasticizers, the glass transition temperature of PVC can be significantly reduced, the melt viscosity of PVC can be reduced, and its fluidity can be improved, making it softer and easier to process to meet the requirements for preparing soft toys. However, adding a large amount of plasticizers leads to the problem of easy plasticizer exudation during use. Since the molecular weight of plasticizers is relatively low, they are prone to migration and seepage under the influence of temperature, pressure or friction media. This phenomenon is usually manifested as the appearance of greasiness and stickiness on the surface of toys, accompanied by yellowing, hardening, embrittlement, and even cracking and deformation. Over time, the flexibility of the PVC material gradually loses, resulting in a decline in the overall performance of the toys.

[0003] In order to further reduce the oil exudation of PVC materials, the following several methods are mainly adopted: First, adding compatibilizers, such as chlorinated polyolefins, can improve the compatibility between plasticizers and PVC and reduce oil exudation; second, adding inhibitors, which can form complexes with plasticizers to delay their migration rate and effectively reduce the oil bleeding phenomenon; third, adding fillers such as nano calcium carbonate and silica can adsorb plasticizers, reduce their free amount, and reduce the risk of oil exudation. The above-mentioned schemes can all reduce the oil exudation of PVC materials. However, due to the large amount of toughening agent added, the corresponding amounts of compatibilizers, inhibitors and fillers also need to increase. Once the amounts of compatibilizers, inhibitors and fillers increase, it will affect the performance of PVC toys, such as greatly reducing the flexibility, tensile strength and impact resistance of PVC, and affecting its processing performance. Summary of the Invention

[0004] In order to solve the problem of oil exudation caused by using a large amount of plasticizers in PVC materials, and the problem that the use of excessive compatibilizers, inhibitors and fillers will lead to a reduction in their performance, the present application provides a high-fluidity PVC material for toys that does not exude oil and a preparation method thereof.

[0005] In the first aspect, the present application provides a high-fluidity PVC material for toys that does not exude oil, adopting the following technical solution: A high-fluidity PVC material for toys that does not exude oil, prepared from the following raw materials in parts by weight: 90 - 110 parts of PVC powder 45 - 55 parts of calcium powder 3 - 5 parts of stabilizer 0.8 - 1.2 parts of lubricant 80 - 100 parts of plasticizer.

[0006] By adopting the above technical solution, the prepared PVC material can effectively inhibit the migration and precipitation of plasticizer, reduce the greasy and sticky phenomena on the surface of toys, and at the same time maintain the high fluidity, good flexibility, tensile strength and impact resistance of the material, which is suitable for manufacturing soft toys that require flexibility and high fluidity.

[0007] Among them, in this application, by adding a large amount of plasticizer, the flexibility, tensile strength and impact resistance of the PVC material are further improved. In this application, the dosage of plasticizer and PVC powder is about 1:1. With a large dosage of plasticizer, the risk of oil bleeding is greater. In this application, an appropriate amount of calcium powder is added, which can adsorb plasticizer, reduce its free amount, and thus reduce the risk of oil bleeding. At the same time, the addition of stabilizer helps to improve the thermal stability and chemical stability of the material, and further inhibits the precipitation of plasticizer.

[0008] The use of stabilizer can effectively inhibit the thermal degradation and oxidative degradation of PVC during processing and use, and extend the service life of the material. In addition, the addition of calcium powder also helps to improve the thermal stability and dimensional stability of the material.

[0009] The addition of calcium powder and lubricant helps to improve the fluidity of the material, reduce the processing difficulty, and at the same time does not affect the flexibility of the final product. The addition of lubricant improves the processing performance of PVC material, reduces the intermolecular friction, and makes the material flow more easily during processing. This optimization not only improves the production efficiency, but also reduces the precipitation of plasticizer caused by improper processing.

[0010] Preferably, the calcium powder is modified calcium powder, which is prepared by the following method: 1) Disperse calcium powder in an ethanol - water mixture, add ammonia water to make the pH 9 - 11 to obtain a suspension; 2) Mix tetraethyl orthosilicate, cetyltrimethylammonium bromide and an organic solvent to obtain a tetraethyl orthosilicate solution; 3) Heat the suspension to 45 - 50 °C, dropwise add the tetraethyl orthosilicate solution. After the dropping is completed, keep the temperature for reaction for 5 - 8 h, filter, wash, take the filter residue, heat it to 500 - 550 °C and keep it for 1 - 2 h to obtain a semi - finished product; 4) Mix the semi - finished product with a silane coupling agent and ethanol, heat it to 40 - 50 °C, react for 1 - 2 h, filter, wash, take the filter residue, and dry it to obtain modified calcium powder.

[0011] By adopting the above technical solution, the specific surface area and porosity of the calcium powder are increased, the adsorption capacity of the calcium powder for the plasticizer is further improved, the migration and precipitation in the PVC matrix are reduced, and meanwhile, its dispersibility and compatibility in the PVC matrix are improved, and the tensile strength and impact resistance of the PVC material are further enhanced.

[0012] Disperse the calcium powder in the ethanol-water mixture, and add ammonia water to adjust the pH to 9-11 to make the surface of the calcium powder negatively charged, enhance its dispersibility in the solution, and at the same time provide a suitable alkaline environment for the subsequent coating reaction. Mix tetraethyl orthosilicate with cetyltrimethylammonium bromide and an organic solvent to form a tetraethyl orthosilicate solution. As a surfactant, cetyltrimethylammonium bromide can adjust the polarity of the solution, promote the hydrolysis and polymerization of tetraethyl orthosilicate, and at the same time prevent the aggregation of silica particles. In the third step, heat the suspension obtained in the first step to 45-50 °C and dropwise add the tetraethyl orthosilicate solution. Under alkaline conditions, tetraethyl orthosilicate will undergo a hydrolysis reaction to generate silanol (Si(OH)4), and then the silanol will further condense to form a silica network. By controlling the reaction temperature and time, silica gradually forms a uniform coating layer on the surface of the calcium powder. After the reaction is completed, filter and wash to remove the unreacted substances to obtain a semi-finished product of calcium powder coated with silica. In the fourth step, heat the semi-finished product to 500-550 °C and keep it for 1-2 hours. The purpose of the high-temperature treatment is to remove cetyltrimethylammonium bromide and at the same time make the silica coating layer denser. Subsequently, mix the semi-finished product with a silane coupling agent and ethanol, heat to 40-50 °C and react for 1-2 hours. The role of the silane coupling agent is to further improve the surface properties of the calcium powder, change it from hydrophilic to lipophilic, further enhance the interfacial compatibility between the calcium powder and the PVC matrix, and enable the modified calcium powder to play a better strengthening and toughening role in the PVC material.

[0013] Preferably, the weight ratio of the calcium powder, the tetraethyl orthosilicate, and the cetyltrimethylammonium bromide is 10:(12-15):(0.3-0.6).

[0014] By adopting the above technical solution, optimizing the dosages of the calcium powder, tetraethyl orthosilicate, and cetyltrimethylammonium bromide can effectively promote the uniform coating of silica on the surface of the calcium powder, make it evenly distributed on the surface of the calcium powder, further improve the adsorption effect on the plasticizer, and reduce its migration and precipitation in the PVC matrix.

[0015] Preferably, the weight of the silane coupling agent is 3%-5% of the weight of the calcium powder.

[0016] By adopting the above technical solution, optimizing the dosages of the silane coupling agent and the calcium powder helps to improve the dispersibility and compatibility of the calcium powder in the PVC matrix and reduce the phenomenon of particle aggregation.

[0017] Preferably, the average particle size of the calcium powder is 50-100 nm.

[0018] By adopting the above technical solution, the average particle size of the calcium powder is optimized, making it have a higher specific surface area and a lower tendency to agglomerate. It can be better dispersed in the PVC matrix, improve its adsorption of plasticizers, reduce its migration and precipitation in the PVC matrix, not only solve the problem of plasticizer precipitation in traditional PVC materials, but also maintain the flexibility and processing performance of the materials. At the same time, it also improves the tensile strength and impact resistance of the PVC materials.

[0019] Preferably, the non-oil-bleeding high-flow PVC material for toys further includes 5-10 parts by weight of a thermoplastic elastomer.

[0020] Thermoplastic elastomer (TPE) has excellent flexibility and elasticity. It can significantly improve the flexibility and elasticity of the material without significantly reducing the processing performance of the PVC material. This is particularly important for toy materials because it can enhance the bending resistance and impact resistance of toys during use and reduce damage caused by external forces. The polymer structure of the thermoplastic elastomer can form better compatibility with the PVC matrix, reducing the migration of plasticizers. This not only improves the long-term stability of the material but also reduces the surface stickiness and discoloration problems caused by oil bleeding.

[0021] Preferably, the stabilizer is composed of a Ca / Zn composite stabilizer and organotin in a weight ratio of 5:(0.5-1.5).

[0022] By adopting the above technical solution, optimizing the type and dosage of the stabilizer can effectively inhibit the thermal degradation of PVC during processing and use. The Ca / Zn composite stabilizer delays the degradation of PVC by neutralizing HCl generated by the thermal decomposition of PVC, replacing unstable chlorine atoms, and capturing free radicals. Organotin further inhibits the release of HCl by forming coordination bonds with unstable chlorine atoms in the PVC molecule. After the two are combined, the thermal stability time of PVC can be significantly increased, and the initial coloring and long-term thermal degradation can be reduced.

[0023] Preferably, the organotin is one of mercapto organotin, dibutyltin maleate, dioctyltin dilaurate or dioctyltin compounds.

[0024] By adopting the above technical solution, optimizing the type of organotin can further improve the formation of stable complexes between tin atoms in organotin and unstable chlorine atoms on the PVC molecular chain, effectively inhibit the release of HCl, improve its thermal stability. At the same time, it reduces the damage of ultraviolet rays to the polymer chain, thereby improving the weather resistance of PVC products under long-term light exposure.

[0025] Preferably, the lubricant is composed of glycerol monostearate and polyethylene wax in a weight ratio of 1:(0.8 - 1.1).

[0026] By adopting the above technical solution, the type and dosage of the lubricant are optimized, the fluidity of the PVC melt is improved, and the adhesion problem of PVC during processing is reduced. Among them, glycerol monostearate is an excellent internal lubricant, which can penetrate into the interior of PVC macromolecules, reduce the intermolecular friction, and thus improve the fluidity of the melt. Polyethylene wax mainly provides external lubrication. By forming a lubricating layer between the PVC melt and the surface of the processing equipment, the adhesion between the melt and the equipment is reduced, and the processing performance is improved. Moreover, the combination of glycerol monostearate and polyethylene wax exhibits good thermal stability during processing, which can reduce the material degradation caused by high temperature.

[0027] In the second aspect, the present application provides a method for preparing a non-oil-separating and highly fluid PVC material for toys, adopting the following technical solution: A method for preparing a non-oil-separating and highly fluid PVC material for toys, comprising the following preparation steps: S1. Stir the PVC powder and 2 / 3 of the plasticizer until the plasticizer is absorbed to obtain a mixture; S2. Mix the mixture, calcium powder, stabilizer, lubricant and the remaining plasticizer, and then extrude and pelletize to obtain a non-oil-separating and highly fluid PVC material for toys.

[0028] By adopting the above technical solution, first stir the PVC powder with 2 / 3 of the plasticizer until the plasticizer is absorbed. This process ensures the preliminary uniform distribution of the plasticizer in the PVC powder, which helps the uniformity of the subsequent mixing process. Premixing can effectively reduce the local supersaturation phenomenon of the plasticizer and reduce the risk of plasticizer precipitation in the subsequent processing.

[0029] To sum up, the present application has the following beneficial effects: 1. By reasonably proportioning the plasticizer, calcium powder, stabilizer and lubricant, this solution can significantly reduce the migration and precipitation of the plasticizer and reduce the oil separation phenomenon. A large amount of plasticizer ensures that the PVC material still has good flexibility, tensile strength and impact resistance. At the same time, calcium powder has the function of adsorbing the plasticizer, which can reduce its free amount in the PVC matrix. At the same time, the addition of the stabilizer helps to improve the thermal stability of the material and further inhibits the precipitation of the plasticizer. Specific Embodiments Examples

[0030] The PVC powder was purchased from Shandong Yueyang New Materials Co., Ltd., with the grade of DG-1000S.

[0031] Example 1 A high-fluidity PVC material for toys that does not exude oil is prepared by the following method: S1. Stir 900 g of PVC powder and 533 g (dioctyl terephthalate) of 2 / 3 of the plasticizer until the plasticizer is absorbed to obtain a mixture; S2. Mix the mixture, 450 g of calcium powder, 30 g of stabilizer (Ca / Zn composite stabilizer), 8 g of lubricant (glycerol monostearate), and 267 g (dioctyl terephthalate) of the remaining plasticizer, and then extrude and pelletize to obtain a high-fluidity PVC material for toys that does not exude oil.

[0032] The average particle size of the calcium powder is 50 nm.

[0033] Example 2 A high-fluidity PVC material for toys that does not exude oil is prepared by the following method: S1. Stir 1000 g of PVC powder and 600 g (dioctyl terephthalate) of 2 / 3 of the plasticizer until the plasticizer is absorbed to obtain a mixture; S2. Mix the mixture, 500 g of calcium powder, 40 g of stabilizer (dibutyltin maleate), 10 g of lubricant (polyethylene wax), and 300 g (dioctyl terephthalate) of the remaining plasticizer, and then extrude and pelletize to obtain a high-fluidity PVC material for toys that does not exude oil.

[0034] The average particle size of the calcium powder is 80 nm.

[0035] Example 3 A high-fluidity PVC material for toys that does not exude oil is prepared by the following method: S1. Stir 1100 g of PVC powder and 667 g (dioctyl terephthalate) of 2 / 3 of the plasticizer until the plasticizer is absorbed to obtain a mixture; S2. Mix the mixture, 550 g of calcium powder, 50 g of stabilizer (mercapto organotin), 12 g of lubricant (polyethylene wax), and 333 g (dioctyl terephthalate) of the remaining plasticizer, and then extrude and pelletize to obtain a high-fluidity PVC material for toys that does not exude oil.

[0036] The average particle size of the calcium powder is 100 nm.

[0037] Example 4 A high-fluidity PVC material for toys that does not exude oil. The difference between this example and Example 1 is that the calcium powder is modified calcium powder and is prepared by the following method: 1) Disperse 450 g of calcium powder in 1000 g of ethanol-water mixture (400 g of ethanol and 600 g of water), add 100 g of ammonia water to make the pH 9 to obtain a suspension; 2) Mix 540 g of tetraethyl orthosilicate, 13.5 g of cetyltrimethylammonium bromide, and 1000 g of an organic solvent (ethanol) to obtain a tetraethyl orthosilicate solution; 3) Heat the suspension to 45 °C, add dropwise the tetraethyl orthosilicate solution. After the addition is complete, keep the temperature for reaction for 5 h, filter, wash, take the filter residue, heat it to 500 °C and keep it for 1 h to obtain a semi-finished product; 4) Mix the semi-finished product with 13.5 g of a silane coupling agent (γ-aminopropyltriethoxysilane) and 50 g of ethanol, heat to 50 °C, react for 2 h, filter, wash, take the filter residue, and dry to obtain modified calcium powder.

[0038] Example 5 A high-fluidity PVC material for toys that does not bleed oil. The difference between this example and Example 1 is that the calcium powder is modified calcium powder, which is prepared by the following method: 1) Disperse 450 g of calcium powder in 1000 g of an ethanol-water mixture (300 g of ethanol and 700 g of water), add 150 g of ammonia water to make the pH 11 to obtain a suspension; 2) Mix 675 g of tetraethyl orthosilicate, 27 g of cetyltrimethylammonium bromide, and 1000 g of an organic solvent to obtain a tetraethyl orthosilicate solution; 3) Heat the suspension to 50 °C, add dropwise the tetraethyl orthosilicate solution. After the addition is complete, keep the temperature for reaction for 8 h, filter, wash, take the filter residue, heat it to 550 °C and keep it for 2 h to obtain a semi-finished product; 4) Mix the semi-finished product with 22.5 g of a silane coupling agent (γ-(methacryloyloxy)propyltrimethoxysilane) and 75 g of ethanol, heat to 50 °C, react for 2 h, filter, wash, take the filter residue, and dry to obtain modified calcium powder.

[0039] Example 6 A high-fluidity PVC material for toys that does not bleed oil. The difference between this example and Example 4 is that no silane coupling agent is added in step 4).

[0040] Example 7 A high-fluidity PVC material for toys that does not bleed oil. The difference between this example and Example 1 is that the average particle size of the calcium powder is 120 nm.

[0041] Example 8 A high-fluidity PVC material for toys that does not bleed oil. The difference between this example and Example 1 is that 50 g of TPE is added in step S2.

[0042] The TPE is purchased from Shanghai Zhaohe Plastic Co., Ltd., and the model is 60A.

[0043] Example 9 A high-fluidity PVC material for toys that does not bleed oil. The difference between this embodiment and Embodiment 4 is that 100 g of TPE is added in Step S2.

[0044] The TPE was purchased from Shanghai Zhaohe Plastic Chemical Co., Ltd. and the model is 60A.

[0045] Embodiment 10 A high-fluidity PVC material for toys that does not bleed oil. The difference between this embodiment and Embodiment 1 is that the stabilizer is composed of a Ca / Zn composite stabilizer and organotin (dibutyltin maleate) in a weight ratio of 5:0.5.

[0046] Embodiment 11 A high-fluidity PVC material for toys that does not bleed oil. The difference between this embodiment and Embodiment 9 is that the stabilizer is composed of a Ca / Zn composite stabilizer and organotin (dibutyltin maleate) in a weight ratio of 5:1.5.

[0047] Embodiment 12 A high-fluidity PVC material for toys that does not bleed oil. The difference between this embodiment and Embodiment 1 is that the lubricant is composed of glycerol monostearate and polyethylene wax in a weight ratio of 1:0.8.

[0048] Embodiment 13 A high-fluidity PVC material for toys that does not bleed oil. The difference between this embodiment and Embodiment 11 is that the lubricant is composed of glycerol monostearate and polyethylene wax in a weight ratio of 1:1.1.

[0049] Comparative Example Comparative Example 1 A high-fluidity PVC material for toys that does not bleed oil. The difference between this comparative example and Embodiment 1 is that silica is used instead of calcium powder.

[0050] Comparative Example 2 A high-fluidity PVC material for toys that does not bleed oil. The difference between this comparative example and Embodiment 1 is that the amount of plasticizer used is 400 g.

[0051] Comparative Example 3 A high-fluidity PVC material for toys that does not bleed oil. The difference between this comparative example and Embodiment 1 is that the amount of calcium powder used is 900 g.

[0052] Testing Method / Experimental Method Mechanical Property Test: The tensile properties of soft PVC were determined according to GB / T 1040.1-2006 "Plastics - Tensile Test Method". Test temperature: 25°C; Tensile rate: 60 mm / min. Test three times and take the average value, accurate to 0.01.

[0053] Migration rate: Immerse 10 g of high-flow PVC material for toys without oil separation in 100 mL of water or 100 mL of anhydrous ethanol at room temperature. The temperature is 40°C and soak for 24 h. Take the leaching solution to detect the migration rate of the PVC material. The experimental data are shown in Table 1: Table 1 Experimental data of Examples 1-13 and Comparative Examples 1-3 Comparing Example 1 with Comparative Example 1, the tensile strength of Comparative Example 1 is higher than that of Example 1, but its elongation at break is lower than that of Example 1, and the migration rate of the material in water and ethanol is higher than that of Example 1; Comparing Example 1 with Comparative Example 2, the migration rate of the high-flow PVC material for toys without oil separation in Comparative Example 2 in water and ethanol is lower than that of Example 1, but the tensile strength and elongation at break of Comparative Example 2 are lower than those of Example 1; Comparing Example 1 with Comparative Example 3, the migration rate of the high-flow PVC material for toys without oil separation in Comparative Example 2 in water and ethanol is lower than that of Example 1, but the tensile strength and elongation at break of Comparative Example 3 are lower than those of Example 1; From the experimental data of Example 1 and Comparative Examples 1-3, it can be seen that by adding an appropriate amount of calcium powder and an appropriate amount of plasticizer in this application, the migration and precipitation of the plasticizer can be effectively inhibited, the greasy and sticky phenomena on the surface of the toy can be reduced, and at the same time, the good flexibility and tensile strength of the material can be maintained.

[0054] Comparing Example 1 with Examples 4-5, the tensile strength and elongation at break of Examples 4-5 are both improved. The migration rate of the high-flow PVC material for toys without oil separation in Examples 4-5 in water and ethanol is lower than that of Example 1, indicating that by using the modified calcium powder prepared in this application, the migration and precipitation of the plasticizer can be effectively reduced, and the flexibility and tensile strength of the material can be improved.

[0055] Comparing Example 4 with Example 6, the tensile strength and elongation at break of Example 6 are both lower than those of Example 4. The migration rate of the high-flow PVC material for toys without oil separation in Example 4 in water and ethanol is lower than that of Example 6, indicating that by adding a silane coupling agent, the migration and precipitation of the plasticizer can be effectively reduced, and the flexibility and tensile strength of the material can be improved.

[0056] Comparing Example 1 with Example 7, the tensile strength and elongation at break of Example 7 are both lower than those of Example 1. The migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 7 are lower than those in Example 1, indicating that optimizing the average particle size of calcium powder can reduce the migration and precipitation of plasticizers and improve the flexibility and tensile strength of the material.

[0057] Comparing Example 1 with Example 8, the tensile strength and elongation at break of Example 8 are both higher than those of Example 1. The migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 8 are lower than those in Example 1; Comparing Example 4 with Example 9, the tensile strength and elongation at break of Example 9 are both higher than those of Example 4. The migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 9 are lower than those in Example 4; From the experimental data of Examples 1 and 8, 4 and 9, it can be seen that adding thermoplastic elastomer is beneficial to improving the tensile strength and elongation at break of the material, while reducing the migration and precipitation of plasticizers.

[0058] Comparing Example 1 with Example 10, the tensile strength and elongation at break of Example 10 are both higher than those of Example 1. The migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 10 are lower than those in Example 1; Comparing Example 9 with Example 11, the tensile strength and elongation at break of Example 11 are both higher than those of Example 9. The migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 11 are lower than those in Example 9; From the experimental data of Examples 1 and 10, 9 and 10, it can be seen that optimizing the type and dosage of stabilizers is beneficial to improving the tensile strength and elongation at break of the material, while reducing the migration and precipitation of plasticizers.

[0059] Comparing Example 1 with Example 12, the migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 12 are lower than those in Example 1; Comparing Example 11 with Example 13, the migration rates of the non-oil-separating high-fluidity PVC material for toys in water and ethanol in Example 13 are lower than those in Example 11; From the experimental data of Examples 1 and 12, 11 and 13, it can be seen that optimizing the type and dosage of lubricants is beneficial to reducing the migration and precipitation of plasticizers in the material.

[0060] This specific embodiment is only an interpretation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high-fluidity PVC material for toys without oil separation, characterized in that: The preparation is obtained by comprising the following raw materials in parts by weight: PVC powder 90-110 parts Calcium powder 45-55 parts 3-5 parts of stabilizer Lubricant 0.8-1.2 parts Plasticizer 80-100 parts.

2. The high-fluidity PVC material for toys without oil separation according to claim 1, characterized in that: The calcium powder is modified calcium powder, which is prepared by the following method: 1) Disperse calcium powder in an ethanol-water mixture, add ammonia water to adjust the pH to 9-11, and obtain a suspension; 2) mixing tetraethyl orthosilicate, hexadecyltrimethylammonium bromide and an organic solvent to obtain a tetraethyl orthosilicate solution; 3) The suspension is heated to 45-50°C, and the ethyl orthosilicate solution is added dropwise. After the addition is completed, the mixture is kept warm for 5-8 hours, filtered, rinsed, and the residue is taken. The mixture is heated to 500-550°C and maintained for 1-2 hours to obtain a semi-finished product; 4) Mix the semi-finished product with silane coupling agent and ethanol, heat to 40-50°C, react for 1-2 hours, filter, rinse, take the filter residue, dry, and obtain modified calcium powder.

3. The high-fluidity PVC material for toys without oil separation according to claim 2, characterized in that: The weight ratio of the calcium powder, the tetraethyl orthosilicate and the hexadecyltrimethylammonium bromide is 10:(12-15):(0.3-0.6).

4. The high-fluidity PVC material for toys without oil separation according to claim 2, characterized in that: The weight of the silane coupling agent is 3%-5% of the weight of the calcium powder.

5. The high-fluidity PVC material for toys without oil separation according to claim 2, characterized in that: The average particle size of the calcium powder is 50-100 nm.

6. The high-fluidity PVC material for toys without oil separation according to claim 1, characterized in that: The non-oil-separating high-fluidity PVC material for toys also includes 5-10 parts by weight of a thermoplastic elastomer.

7. The high-fluidity PVC material for toys without oil separation according to claim 1, characterized in that: The stabilizer is composed of a Ca / Zn composite stabilizer and organic tin in a weight ratio of 5: (0.5-1.5).

8. The high-fluidity PVC material for toys without oil separation according to claim 1, characterized in that: The organotin is one of organotin thiol, dibutyltin maleate, di-n-octyltin dilaurate or dioctyltin compound.

9. The high-fluidity PVC material for toys without oil separation according to claim 1, characterized in that: The lubricant is composed of glyceryl monostearate and polyethylene wax in a weight ratio of 1: (0.8-1.1).

10. A method for preparing a high-fluidity PVC material for toys without oil separation as claimed in any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: S1. Stir PVC powder and 2 / 3 of plasticizer until the plasticizer is absorbed to obtain a mixture; S2, mixing the mixture calcium powder, stabilizer, lubricant and remaining plasticizer, and then extruding and granulating to obtain a high-fluidity PVC material for toys without oil separation.

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