Multifunctional composite foaming agent for PVC soles and preparation method thereof

Abstract

The invention relates to the technical field of foaming materials, in particular to a multifunctional composite foaming agent for PVC soles and a preparation method thereof.The multifunctional composite foaming agent is prepared from, by mass, 80-90 parts of a modified rosin-based foaming agent, 9-11 parts of a dispersing agent, 10-15 parts of functional filler, 4-7 parts of pentaerythritol, 4-6 parts of a foaming regulator, 15-17 parts of a lubricating agent and 1-3 parts of a plasticizing accelerant; the functional filler is a modified polystyrene-maleic anhydride modified fiber. The multifunctional composite foaming agent for the PVC sole has the advantages that the foaming is compact and stable, the PVC sole material has certain flame retardant property, and the heat resistance, aging resistance, tensile property and wear resistance of the PVC sole material can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming materials, and particularly relates to a multifunctional composite foaming agent for PVC soles and a preparation method thereof. Background Art

[0002] PVC sole materials are a type of plastic material mainly composed of polyvinyl chloride. Due to their wear resistance, corrosion resistance, and waterproof properties, they are widely used in the manufacture of soles. PVC soles have good softness and elasticity, while providing good wear resistance and anti-slip performance. The manufacturing process is relatively simple, so they are very common in footwear products. However, the development of PVC materials is limited due to their poor high-temperature resistance and aging performance.

[0003] Foaming agents are an indispensable chemical additive in the manufacturing process of PVC soles, mainly used for producing lightweight and elastic foamed PVC soles. Commonly used foaming agents include azodicarbonamide, whose addition amount in injection-molded foamed products is 0.5 - 1.0 PHR, and in compression-molded foamed products is 5 - 6 PHR. The addition of foaming agents can significantly reduce the density of PVC soles, improve their cushioning performance and wearing comfort.

[0004] However, the foaming agents prepared by the existing technologies have some advantages and disadvantages. For example, they can achieve good foaming effects at relatively low addition amounts, improving the lightweight and comfort of products, etc. However, the disadvantages are also relatively obvious, such as cost, environmental impact, and operation difficulty during the production process, etc. In response to the above technical problems, Patent No. CN111205503B discloses "Foaming Agent Material, Foaming Agent Masterbatch and Their Preparation Methods". The foaming agent material of this method includes a coating layer and a core layer. The coating layer wraps around the outer layer of the core layer. The coating layer contains boron, silicon, and aluminum elements, and the core layer contains sodium bicarbonate. The foaming agent masterbatch includes the foaming agent material, matrix resin, compatibilizer, and antioxidant. The foaming agent prepared by this method can meet the melting processing requirements of different types of resins. Another example is CN104310848A, which discloses "Cement Foaming Agent and Its Preparation Process", prepared from sodium hydroxide, rosin, bone glue, starch, triethanolamine, and water as the main raw materials. This foaming agent has strong foaming ability, low cost, will not show stratification, is easy to implement, and the process is simple.

[0005] However, the foaming agents in the above-mentioned disclosed patents are not suitable for use in sole materials. In order to improve the user experience, the requirements for sole foaming materials are higher. At the same time, due to the weak anti-aging performance of PVC soles, it is urgent to develop a composite foaming agent suitable for PVC soles and capable of improving the anti-aging performance and tensile performance of PVC soles. Summary of the Invention

[0006] The main object of the present invention is to provide a multifunctional composite foaming agent for PVC soles and a preparation method thereof. The multifunctional composite foaming agent can avoid the situation that rosin foaming agent cannot be directly used in PVC sole materials. At the same time, the composite foaming agent has certain flame retardant properties, can improve the anti-aging and tensile properties of PVC soles, and the generated bubbles are dense and stable.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a multifunctional composite foaming agent for PVC soles, which comprises the following components in parts by mass: 80-90 parts of modified rosin-based foaming agent, 9-11 parts of dispersant, 10-15 parts of functional filler, 4-7 parts of pentaerythritol, 4-6 parts of foaming regulator, 15-17 parts of lubricant and 1-3 parts of plasticization promoter; the functional filler is modified polystyrene-maleic anhydride modified fiber.

[0009] In some embodiments, each part of the modified rosin-based foaming agent comprises the following components in parts by mass: 40-50 parts of foaming agent, 3-5 parts of co-foaming agent, 20-25 parts of stabilizer, 6-8 parts of foaming homogenizer and 6-10 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:(0.6-0.8).

[0010] In some embodiments, the structure of the modified rosin is shown in Formula I

[0011] wherein R is an alkyl group with 18-22 carbon atoms.

[0012] In some embodiments, the preparation method of the modified rosin comprises the following steps:

[0013] S1. Mix abietic acid with isopropanolamine, concentrated sulfuric acid and dichloromethane, heat up to 50-60 °C and stir at a constant temperature for 12-16 h. After the reaction is completed, cool to room temperature and adjust the pH of the system to 6-7. Extract with ethyl acetate and combine the organic phases. After concentration under reduced pressure and drying, column chromatography is carried out to obtain the compound shown in Formula II

[0014]

[0015] S2. Mix the compound shown in Formula II in step S1 with R-Cl, add it to the first solvent, add an acid-binding agent, heat up to 35-45 °C and stir at a constant temperature for 22-24 h. After the reaction is completed, extract with ethyl acetate, combine the organic phases and concentrate and dry under reduced pressure to obtain the compound shown in Formula III

[0016]

[0017] S3. Dissolve the compound shown in Formula III in step S2 in a first solvent, add maleic acid and p-toluenesulfonic acid, heat to 115 - 125 °C, stir at a constant temperature for 24 - 25 h. After the reaction is completed, immerse the solution in an ice-water bath, filter, recrystallize with glacial acetic acid, then dissolve the solid product in ethyl acetate, add n-hexane with a volume 10 - 15 times that of ethyl acetate to precipitate, and dry to obtain the compound shown in Formula IV.

[0018] the compound shown

[0019]

[0020] S4. Mix the compound shown in Formula IV in step S1, isopropanolamine, concentrated sulfuric acid and dichloromethane, heat to 50 - 60 °C, stir at a constant temperature for 12 - 16 h. After the reaction is completed, cool to room temperature, adjust the pH of the system to 6 - 7, extract with ethyl acetate, combine the organic phases, concentrate under reduced pressure and dry, then perform column chromatography to obtain the compound shown in Formula V.

[0021]

[0022] S5. Mix the compound shown in Formula V in step S4 with 2-bromo-5-chlorobenzoic acid, add a second solvent, add an acid-binding agent, heat to 35 - 45 °C, stir at a constant temperature for 22 - 24 h. After the reaction is completed, concentrate under reduced pressure and dry to obtain Compound A.

[0023] S6. Mix Compound A in step S5 with R-Cl, add a first solvent, add an acid-binding agent, heat to 35 - 45 °C, stir at a constant temperature for 22 - 24 h. After the reaction is completed, concentrate under reduced pressure and dry to obtain the compound shown in Formula I.

[0024] In some embodiments, the method for preparing the sodium bicarbonate microcapsules comprises the following steps:

[0025] (1) Dissolve sodium bicarbonate in water to obtain an aqueous phase;

[0026] (2) Dissolve polymethyl methacrylate in ethyl acetate, add a surfactant to obtain an oil phase;

[0027] (3) Mix the aqueous phase in step (1) with the oil phase in step (2), ultrasonically disperse for 10 - 20 min, and then stir in a homogenizing mixer to form a uniform and stable emulsion;

[0028] (4) Spray-dry the emulsion in step (3) at 60 - 80 °C to obtain sodium bicarbonate microcapsules.

[0029] In some embodiments, the dispersant is one or more of high molecular wax, DY-222, and EP-316.

[0030] In some embodiments, the foaming regulator is one or more of ZB-760, ZB-530, and HF530.

[0031] In some embodiments, the lubricant is one or more of 815Z, L-1000, A-C629, DY-222, and LA-B10.

[0032] In some embodiments, the plasticization promoter is PA-20 and / or A-C316A.

[0033] In some embodiments, the method for preparing the modified polystyrene-maleic anhydride modified fiber comprises the following steps:

[0034] A1. Mix maleic anhydride with thionyl chloride, dropwise add N,N-dimethylformamide, stir at room temperature for 9 - 10 h, add ice water to quench, and perform extraction to obtain acyl chloride maleic acid;

[0035] A2. Mix the acyl chloride maleic anhydride in step A1 with 1,3-propanediamine, add a solvent, cool down to 0 - 5 °C, add an acid-binding agent, stir at a constant temperature for 12 - 20 h, after the reaction ends, concentrate under reduced pressure and dry, and perform column chromatography to obtain the compound shown in formula VI;

[0036]

[0037] A3. Under an inert gas atmosphere, mix the compound shown in formula VI in step A2 with 3,5-di-tert-butylsalicylaldehyde, add N,N-dimethylformamide, add potassium carbonate, heat up to 70 - 80 °C, stir at a constant temperature for 12 - 16 h, after the reaction ends, cool down to room temperature, concentrate under reduced pressure and dry to obtain compound A;

[0038] A4. Mix maleic anhydride with hydrotalcite, add ethanol, heat up to 60 - 70 °C, stir for 16 - 18 h, after the reaction ends, filter and dry to obtain hydrotalcite grafted with maleic anhydride;

[0039] A5. Mix compound A in step A3, the hydrotalcite grafted with maleic anhydride in step A4, and styrene, add an initiator and 1,4-dioxane, introduce an inert protective gas, heat up to 60 - 70 °C, stir at a constant temperature for 1 - 2 h, after the reaction ends, cool down to room temperature, add petroleum ether until no precipitation occurs, filter and dry to obtain modified polystyrene-maleic anhydride;

[0040] A6. Mix the modified polystyrene-maleic anhydride with glass fiber, add ethanol, heat up to 60 - 70 °C, stir for 16 - 18 h, after the reaction ends, centrifuge and filter to obtain the modified polystyrene-maleic anhydride modified fiber.

[0041] The PVC material itself has poor anti-aging properties, and its easy aging property has limited its application. Moreover, as a sole material, more stringent requirements are imposed on the performance of the PVC material, such as being lightweight and highly elastic. However, most of the commercially available PVC sole materials currently add various additive components to reinforce their performance. For example, antioxidants are added to improve the anti-aging performance of the PVC sole material. However, due to the huge difference in molecular weight between the polymer material and the small molecule, poor mutual solubility is likely to occur, resulting in precipitation and affecting the quality of the PVC sole.

[0042] The sole foaming agent prepared by using the modified polystyrene-maleic anhydride modified fiber of the present application as a filler can be well applied to the PVC sole material. In addition, the applicant also found that the foaming agent of the present application can not only improve the anti-aging performance of the PVC sole material, but also improve the anti-tensile performance of the PVC sole and enhance the toughness of the sole. The reason may be that, on the one hand, the structure of the modified polystyrene-maleic anhydride modified fiber contains a large number of hindered phenol structures, which can capture free radicals and improve the anti-aging performance of the PVC sole material; on the other hand, the modified polystyrene-maleic anhydride contains a large number of hydroxyl groups, which can react with the carboxyl groups in the glass fiber structure to form a cross-linked network structure, thereby improving the tensile performance of the PVC sole material and enhancing the toughness of the sole.

[0043] In addition, by graft-modifying hydrotalcite with maleic anhydride in the present application, the dispersion performance of hydrotalcite in the PVC sole material can be improved, further improving the heat resistance and wear resistance of the PVC sole material, and at the same time preventing the poor mutual solubility between hydrotalcite and the PVC sole material from causing precipitation and affecting the quality of the PVC sole.

[0044] In some embodiments, in step A1, the mass ratio of maleic anhydride to thionyl chloride is 1:(3-5).

[0045] Preferably, in step A1, the mass ratio of maleic anhydride to thionyl chloride is 1:4.

[0046] In some embodiments, in step A2, the molar ratio of the acyl chloride maleic anhydride to 1,3-propanediamine is 1:(2-2.2).

[0047] Preferably, in step A2, the molar ratio of the acyl chloride maleic anhydride to 1,3-propanediamine is 1:2.1.

[0048] By regulating the molar ratio of the acyl chloride maleic anhydride to 1,3-propanediamine in the present application, both acyl chloride groups in the acyl chloride maleic anhydride can undergo an addition reaction with 1,3-propanediamine to form amides, thereby further increasing the amine group content, and the content of the hindered amine structure can be increased in the subsequent reaction, improving the anti-aging performance of the PVC sole.

[0049] In some embodiments, in step A3, the molar ratio of the compound shown in formula VI, 3,5-di-tert-butylsalicylaldehyde, and potassium carbonate is 1:(2 - 2.2):(1.2 - 1.4).

[0050] Preferably, in step A3, the molar ratio of the compound shown in formula VI, 3,5-di-tert-butylsalicylaldehyde, and potassium carbonate is 1:2.1:1.3.

[0051] By regulating the molar ratio of the compound shown in formula VI, 3,5-di-tert-butylsalicylaldehyde, and potassium carbonate in this application, the content of the hindered phenol structure in the modified polystyrene-maleic anhydride modified fiber can be increased, and the anti-aging performance of the PVC sole material can be improved.

[0052] In some embodiments, in step A4, the mass ratio of maleic anhydride to hydrotalcite is 1:(8 - 9).

[0053] In some embodiments, in step A5, the mass ratio of compound A, hydrotalcite graft-modified maleic anhydride, and styrene is 1:(1.5 - 1.7):(5 - 5.5).

[0054] Preferably, in step A5, the mass ratio of compound A, hydrotalcite graft-modified maleic anhydride, and styrene is 1:1.6:5.2.

[0055] By regulating the mass ratio of compound A, hydrotalcite graft-modified maleic anhydride, and styrene in this application, the wear resistance and high-temperature resistance of the PVC sole material can be prevented from decreasing, and at the same time, the tensile properties of the PVC sole material can be prevented from weakening.

[0056] In some embodiments, in step A6, the mass ratio of the modified polystyrene-maleic anhydride to glass fiber is 1:(4 - 6).

[0057] Preferably, in step A6, the mass ratio of the modified polystyrene-maleic anhydride to glass fiber is 1:5.

[0058] On the other hand, the present invention provides a preparation method of a multifunctional composite foaming agent for PVC soles, including the following steps: mixing a modified rosin-based foaming agent, a dispersant, a functional filler, pentaerythritol, a foaming regulator, a lubricant, and a plasticization promoter evenly to obtain the multifunctional composite foaming agent for PVC soles.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] (1) The present invention uses a modified rosin-based foaming agent, a dispersant, a functional filler, pentaerythritol, a foaming regulator, a lubricant, and a plasticization promoter as main raw materials to prepare a multifunctional composite foaming agent for PVC soles. This composite foaming agent not only has dense and stable foaming, but also enables the PVC sole material to have certain flame retardant properties. At the same time, it can also improve the heat resistance, anti-aging, tensile properties, and wear resistance of the PVC sole material.

[0061] (2) The modified polystyrene-maleic anhydride modified fiber of the present invention can not only improve the anti-aging performance of the PVC sole material, but also improve the anti-tensile performance of the PVC sole and enhance the toughness of the sole. In addition, by grafting and modifying hydrotalcite with maleic anhydride, the dispersion performance of hydrotalcite in the PVC sole material can be improved, further enhancing the heat resistance and wear resistance of the PVC sole material. At the same time, it can prevent the poor compatibility between hydrotalcite and the PVC sole material from causing precipitation and affecting the quality of the PVC sole.

[0062] (3) By using a specific molar ratio of maleic anhydride chloride and 1,3-propanediamine, the present invention enables both acyl chloride groups in maleic anhydride chloride to undergo an addition reaction with 1,3-propanediamine to form amides, thereby further increasing the amine group content. In subsequent reactions, the content of the hindered amine structure can be increased, improving the anti-aging performance of the PVC sole.

[0063] (4) By regulating the molar ratio of the compound shown in Formula VI, 3,5-di-tert-butylsalicylaldehyde, and potassium carbonate, the present invention can increase the content of the hindered phenol structure in the modified polystyrene-maleic anhydride modified fiber, improving the anti-aging performance of the PVC sole material. Description of the Drawings

[0064] Figure 1 1H NMR spectrum of the modified rosin prepared in Preparation Example 1 of the present invention. Detailed Embodiments

[0065] The following will describe the present invention in conjunction with specific implementation schemes. It should be noted that the following examples are examples of the present invention, only for explaining the present invention, and not for limiting the present invention. Without departing from the gist or scope of the present invention, other combinations and various improvements within the concept of the present invention can be made.

[0066] In the following preparation examples and examples, the CAS number of polymethyl methacrylate is 9011-14-7; hydrotalcite was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.; polystyrene-maleic anhydride copolymer was purchased from Hubei Dalili Chemical Co., Ltd.; glass fiber was purchased from Tai'an Hongtong New Materials Co., Ltd.; polymer wax was purchased from Ningxia Tianrun Jiaze New Materials Technology Co., Ltd.; ZB-760 was purchased from Zibo Huaxing Auxiliary Co., Ltd.; 815Z was purchased from Beijing LuHang HangTe Technology Co., Ltd.; A-C316A was purchased from Dongguan Boyang New Materials Co., Ltd.

[0067] Preparation Example 1

[0068] The preparation method of modified rosin comprises the following steps:

[0069] S1. Mix 0.1 mol of abietic acid with 0.12 mol of isopropanolamine, 18.1 g of concentrated sulfuric acid with a mass concentration of 98%, and 270 mL of dichloromethane, heat up to 55 °C and stir at a constant temperature for 14 h. After the reaction is completed, cool down to 27 °C and adjust the pH of the system to 6 with 2 mol / L sodium hydroxide solution. After extraction with ethyl acetate, combine the organic phases, concentrate under reduced pressure and dry, and then perform column chromatography to obtain the compound shown in Formula II

[0070]

[0071] S2. Mix 0.1 mol of the compound shown in Formula II in step S1 with 0.21 mol of octadecyl chloride, add them to 330 mL of toluene, add 0.13 mol of sodium bicarbonate, heat up to 40 °C and stir at a constant temperature for 23 h. After the reaction is completed, extract with chloroform, combine the organic phases, concentrate under reduced pressure and dry to obtain the compound shown in Formula III

[0072] wherein R is a C18 alkyl group;

[0073] S3. Dissolve 0.1 mol of the compound shown in Formula III in step S2 in 630 mL of chloroform, add 0.11 mol of maleic acid and 0.2 g of p-toluenesulfonic acid, heat up to 120 °C and stir at a constant temperature for 24 h. After the reaction is completed, immerse the solution in an ice-water bath, filter, recrystallize with glacial acetic acid, then dissolve the solid product with ethyl acetate, add n-hexane with a volume 12 times that of ethyl acetate to precipitate, and dry to obtain the compound shown in Formula IV

[0074]

[0075] S4. Mix 0.1 mol of the compound shown in Formula IV in Step S1, 0.21 mol of isopropanolamine, 44 g of concentrated sulfuric acid with a mass concentration of 98%, and 750 mL of dichloromethane. Heat the mixture to 55 °C and stir it at a constant temperature for 14 h. After the reaction is completed, cool it to 27 °C. Adjust the pH of the system to 7 with 2 mol / L sodium hydroxide solution. Extract with ethyl acetate and combine the organic phases. After concentration under reduced pressure and drying, perform column chromatography to obtain the compound shown in Formula V.

[0076]

[0077] S5. Mix 0.1 mol of the compound shown in Formula V in Step S4 with 0.29 mol of 2-bromo-5-chlorobenzoic acid, add 850 mL of methanol, add 0.12 mol of sodium bicarbonate, heat the mixture to 40 °C and stir it at a constant temperature for 23 h. After the reaction is completed, concentrate and dry it under reduced pressure to obtain Compound A.

[0078] S6. Mix 0.1 mol of Compound A in Step S5 with 0.11 mol of octadecyl chloride, add 1.5 L of toluene, add 0.13 mol of sodium bicarbonate, heat the mixture to 40 °C and stir it at a constant temperature for 23 h. After the reaction is completed, concentrate and dry it under reduced pressure to obtain the compound shown in Formula I, which is the modified rosin.

[0079] Wherein R is a C18 alkyl group.

[0080] NMR spectrum analysis of modified rosin: δ7.85 (d, J = 2.3 Hz, 2H, H adjacent to formic acid on the two benzene rings in the upper right corner), 7.64 (d, J = 8.5 Hz, 2H, two H adjacent to -Br on the two benzene rings in the upper right corner), 7.56 (d, J = 8.7 Hz, 1H, one H adjacent to Br on the benzene ring in the lower right corner), 7.45 (s, 1H, one H adjacent to formic acid on the benzene ring in the lower right corner), 7.16 (d, J = 8.4 Hz, 2H, two H meta to Br on the two benzene rings in the upper right corner), 6.96 (d, J = 8.8 Hz, 1H, one H meta to Br on the benzene ring in the lower right corner), 4.28 (d, J = 5.9 Hz, 2H, two H on the -CH2- near the five-membered ring of the carbon chain with two carbons between N and O connecting two benzene rings), 4.19 (d, J = 9.7 Hz, 2H, two H on the -CH2- near the five-membered ring of the carbon chain with two carbons between N and O connecting one benzene ring), 4.08 (d, J = 13.2 Hz, 2H, -CH2- near O of the carbon chain with two carbons between N and O connecting two long carbon chains), 3.92 (d, J = 19.7 Hz, 1H, one H connecting -CH3 of the carbon chain with two carbons between N and O connecting two benzene rings), 3.84 (d, J = 12.5 Hz, 1H, one H on the ring connecting formic acid at the lower right corner of the five-membered ring), 3.68 (d, J = 7.7 Hz, 1H, one H connecting -CH3 of the carbon chain with two carbons between N and O connecting one benzene ring), 3.48 (d, J = 9.5 Hz, 2H, two H on the first C of the carbon chain beside N connecting one benzene ring), 3.31 - 3.21 (m, 2H, H on the first C not connected to a carbon chain beside N connecting two C chains), 3.09 (d, J = 10.1 Hz, 2H, two H above on the five-membered ring), 2.68 (d, J = 6.1 Hz, 2H, H on the first carbon of the two C chains on N), 2.62 - 2.55 (m, 2H, same as above), 2.31 (m, 2H, one H on the C connected to two methyl groups inside the five-membered ring. One H on the upper C at the junction of the six-membered ring with a double bond and the six-membered ring), 1.97 (t, J = 6.2 Hz, 3H, five H at the top and lower left and right corners of the left six-membered ring, two of which appear among the following 16), 1.76 - 1.39 (m, 16H), 1.38 - 1.21 (m, 88H, both the previous 16H and these come from carbon chains, six-membered rings and two -CH3 above), 1.17 - 1.13 (m, 6H, -CH3 below the six-membered ring and -CH3 closest to N connecting two C chains), 1.05 (d, J = 6.8 Hz, 6H, two -CH3 inside the five-membered ring), 0.89 (t, J = 4 Hz, 9H, -CH3 at the end of all carbon chains), 0.83 (t, J = 1.6 Hz, 3H, -CH3 between the two six-membered rings).

[0081] Preparation Example 2

[0082] A method for preparing sodium bicarbonate microcapsules, comprising the following steps:

[0083] (1) Dissolve 10 g of sodium bicarbonate in 110 mL of water to obtain an aqueous phase;

[0084] (2) Dissolve 21 g of polymethyl methacrylate in 440 mL of ethyl acetate, and add 0.2 g of Tween-80 to obtain an oil phase;

[0085] (3) Mix the aqueous phase in step (1) with the oil phase in step (2), ultrasonically disperse for 15 min, and then stir in a homogenizing mixer to form a uniform and stable emulsion;

[0086] (4) Spray-dry the emulsion in step (3) at 70 °C to obtain sodium bicarbonate microcapsules.

[0087] Preparation Example 3

[0088] A method for preparing modified polystyrene-maleic anhydride modified fibers, comprising the following steps:

[0089] A1. Mix 10 g of maleic anhydride with 40 g of thionyl chloride, dropwise add 0.5 mL of N,N-dimethylformamide, stir at 27 °C for 9 h, add ice water to quench, and extract to obtain acid chloride maleic acid;

[0090] A2. Mix 0.1 mol of the acid chloride maleic anhydride in step A1 with 0.21 mol of 1,3-propanediamine, add 200 mL of N,N-dimethylformamide, cool to 3 °C, add 0.12 mol of sodium bicarbonate, stir at a constant temperature for 16 h, after the reaction is completed, concentrate and dry under reduced pressure, and perform column chromatography to obtain the compound shown in formula VI;

[0091]

[0092] A3. Under a N2 atmosphere, mix 0.1 mol of the compound shown in formula VI in step A2 with 0.21 mol of 3,5-di-tert-butylsalicylaldehyde, add 250 mL of N,N-dimethylformamide, add 0.12 mol of potassium carbonate, heat to 75 °C, stir at a constant temperature for 14 h, after the reaction is completed, cool to 27 °C, concentrate and dry under reduced pressure to obtain compound A;

[0093] A4. Mix 10 g of maleic anhydride with 85 g of hydrotalcite, add 500 mL of ethanol, heat to 65 °C, stir for 17 h, after the reaction is completed, filter and dry to obtain hydrotalcite grafted with maleic anhydride;

[0094] A5. Mix 10 g of compound A in step A3, 16 g of hydrotalcite grafted with maleic anhydride in step A4, and 52 g of styrene, add 0.1 g of azobisisobutyronitrile and 560 mL of 1,4-dioxane, introduce N2 gas, heat up to 65 °C and stir at a constant temperature for 1 h. After the reaction, cool down to 27 °C, add petroleum ether until no precipitation occurs, filter, and dry to obtain modified polystyrene-maleic anhydride.

[0095] A6. Mix 30 g of modified polystyrene-maleic anhydride with 150 g of glass fiber, add 1 L of ethanol, heat up to 65 °C, and stir for 17 h. After the reaction, centrifuge and filter to obtain modified polystyrene-maleic anhydride modified fiber.

[0096] Preparation Example 4

[0097] The preparation method of modified polystyrene-maleic anhydride modified fiber is the same as that of Preparation Example 3, except that 1,3-propanediamine is 0.1 mol.

[0098] Preparation Example 5

[0099] The preparation method of modified polystyrene-maleic anhydride modified fiber is the same as that of Preparation Example 3, except that 3,5-di-tert-butylsalicylaldehyde is 0.1 mol.

[0100] Preparation Example 6

[0101] The preparation method of modified polystyrene-maleic anhydride modified fiber is the same as that of Preparation Example 3, except that the hydrotalcite grafted with maleic anhydride is 10 g.

[0102] Preparation Example 7

[0103] The preparation method of modified polystyrene-maleic anhydride modified fiber is the same as that of Preparation Example 3, except that the hydrotalcite grafted with maleic anhydride is 20 g.

[0104] Preparation Example 8

[0105] The preparation method of polystyrene-maleic anhydride modified fiber includes the following steps: Mix 30 g of polystyrene-maleic anhydride copolymer with 150 g of glass fiber, add 1 L of ethanol, heat up to 65 °C, and stir for 17 h. After the reaction, centrifuge and filter to obtain modified polystyrene-maleic anhydride modified fiber.

[0106] Example 1

[0107] A multifunctional composite foaming agent for PVC soles, comprising the following components in parts by mass: 85 parts of modified rosin-based foaming agent, 10 parts of high molecular wax, 13 parts of modified polystyrene-maleic anhydride modified fiber, 5 parts of pentaerythritol, 5 parts of ZB-760, 16 parts of 815Z, and 2 parts of AC-316A.

[0108] Among them, each part of the modified rosin-based foaming agent comprises the following components in parts by mass: 45 parts of foaming agent, 4 parts of P-533J, 23 parts of stabilizer, 7 parts of titanate coupling agent, and 8 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.7; the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsules are prepared from Preparation Example 2, the modified polystyrene-maleic anhydride modified fiber is prepared from Preparation Example 3, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:1:1.

[0109] The preparation method of the multifunctional composite foaming agent for PVC soles comprises the following steps: mixing the modified rosin-based foaming agent, high molecular wax, modified polystyrene-maleic anhydride modified fiber, pentaerythritol, ZB-760, 815Z, and A-C316A and stirring evenly to obtain the multifunctional composite foaming agent for PVC soles.

[0110] Example 2

[0111] A multifunctional composite foaming agent for PVC soles, comprising the following components in parts by mass: 80 parts of modified rosin-based foaming agent, 9 parts of high molecular wax, 10 parts of modified polystyrene-maleic anhydride modified fiber, 4 parts of pentaerythritol, 4 parts of ZB-760, 15 parts of 815Z, and 1 part of AC-316A.

[0112] Among them, each part of the modified rosin-based foaming agent comprises the following components in parts by mass: 45 parts of foaming agent, 4 parts of P-533J, 23 parts of stabilizer, 7 parts of titanate coupling agent, and 8 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.7; the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsules are prepared from Preparation Example 2, the modified polystyrene-maleic anhydride modified fiber is prepared from Preparation Example 3, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:1:1.

[0113] The preparation method of the multifunctional composite foaming agent for PVC soles comprises the following steps: mixing the modified rosin-based foaming agent, high molecular wax, modified polystyrene-maleic anhydride modified fiber, pentaerythritol, ZB-760, 815Z, and A-C316A and stirring evenly to obtain the multifunctional composite foaming agent for PVC soles.

[0114] Example 3

[0115] A multifunctional composite foaming agent for PVC soles, comprising the following components in parts by mass: 90 parts of a modified rosin-based foaming agent, 11 parts of a high molecular weight wax, 15 parts of a modified polystyrene-maleic anhydride modified fiber, 7 parts of pentaerythritol, 6 parts of ZB-760, 17 parts of 815Z, and 3 parts of AC-316A.

[0116] Among them, each part of the modified rosin-based foaming agent comprises the following components in parts by mass: 45 parts of a foaming agent, 4 parts of P-533J, 23 parts of a stabilizer, 7 parts of a titanate coupling agent, and 8 parts of urea; the foaming agent comprises a modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.7; the modified rosin is prepared by Preparation Example 1, the sodium bicarbonate microcapsules are prepared by Preparation Example 2, the modified polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 3, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate in a mass ratio of 1:1:1.

[0117] A preparation method of a multifunctional composite foaming agent for PVC soles, comprising the following steps: mixing and stirring evenly the modified rosin-based foaming agent, the high molecular weight wax, the modified polystyrene-maleic anhydride modified fiber, pentaerythritol, ZB-760, 815Z, and A-C316A to obtain the multifunctional composite foaming agent for PVC soles.

[0118] Example 4

[0119] A multifunctional composite foaming agent for PVC soles and a preparation method thereof, the specific implementation manner is the same as that of Example 1, the difference is that the modified polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 4.

[0120] Example 5

[0121] A multifunctional composite foaming agent for PVC soles and a preparation method thereof, the specific implementation manner is the same as that of Example 1, the difference is that the modified polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 5.

[0122] Example 6

[0123] A multifunctional composite foaming agent for PVC soles and a preparation method thereof, the specific implementation manner is the same as that of Example 1, the difference is that the modified polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 6.

[0124] Example 7

[0125] A multifunctional composite foaming agent for PVC soles and a preparation method thereof, the specific implementation manner is the same as that of Example 1, the difference is that the modified polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 7.

[0126] Comparative Example 1

[0127] A multifunctional composite foaming agent for PVC soles and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that an equal mass portion of glass fiber is used instead of modified polystyrene-maleic anhydride modified fiber.

[0128] Comparative Example 2

[0129] A multifunctional composite foaming agent for PVC soles and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that an equal mass portion of polystyrene-maleic anhydride modified fiber is used instead of modified polystyrene-maleic anhydride modified fiber, and the polystyrene-maleic anhydride modified fiber is prepared by Preparation Example 8.

[0130] Performance Test:

[0131] 60 parts of PVC and 1 part of a multifunctional composite foaming agent for PVC soles are mixed by weight, and the mixture is added into a high-speed mixer and fully stirred for 10 minutes. After the mixing is completed, the raw materials are put into a shoe mold through an extruder, and the shoe mold is put into a foaming machine for primary foaming at a foaming temperature of 150° C. After the foaming is completed, the sheet is taken out and fully cooled; after cooling, the sheet is put into a molding machine for secondary molding, and trimmed and trimmed to obtain the PVC sole material.

[0132] (1) Heat resistance test: Tested according to GB1035-1970 "Plastic Heat Resistance (Martin) Test Method" standard;

[0133] (2) Tensile strength test: Tested in accordance with GBT1040.1-2006 "Determination of tensile properties of plastics Part 1: General principles";

[0134] (3) Anti-aging test: The sample was placed in a thermal oxidation aging at 100°C for 72 h, and then the tensile strength test was performed according to method (2). The tensile strength retention rate was calculated according to the following formula:

[0135] Tensile strength retention rate (%) = (A1 / A0) × 100%;

[0136] Where A1 is the tensile strength of the material after aging; A0 is the tensile strength of the material before aging.

[0137] The PVC sole materials prepared in the embodiments and comparative examples were tested according to the above test method. The results are shown in Table 1.

[0138] Table 1

[0139]

[0140]

[0141] According to the data analysis in Table 1, it can be seen that the soles made from the blowing agents in Examples 1 to 3 have excellent heat resistance, tensile properties, and anti-aging properties. In Example 4, due to the change in the molar ratio of maleic anhydride chloride and 1,3-propanediamine, the anti-aging property of the obtained sole is weakened; in Example 5, due to the change in the molar ratio of the compound shown in Formula VI and 3,5-di-tert-butylsalicylaldehyde, the anti-aging property of the sole is also weakened; in Example 6, due to the change in the mass ratio of Compound A, hydrotalcite graft-modified maleic anhydride, and styrene, the heat resistance of the sole decreases; in Example 7, due to the change in the mass ratio of Compound A, hydrotalcite graft-modified maleic anhydride, and styrene, the increase in the content of hydrotalcite graft-modified maleic anhydride weakens the tensile property of the sole; in Comparative Example 1, due to the use of equal mass parts of glass fiber instead of modified polystyrene-maleic anhydride modified fiber, the heat resistance temperature and anti-aging property of the sole decrease significantly, and the tensile strength also weakens due to the decrease in crosslinking density; in Comparative Example 1, due to the use of equal mass parts of polystyrene-maleic anhydride modified fiber instead of modified polystyrene-maleic anhydride modified fiber, the heat resistance temperature and anti-aging property of the sole decrease significantly, but due to a slight decrease in crosslinking density, the decrease in tensile strength is not obvious.

[0142] The present invention can also have various other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A multifunctional composite foaming agent for PVC soles, characterized in that, It includes the following components in parts by mass: 80 to 90 parts of modified rosin-based foaming agent, 9 to 11 parts of dispersant, 10 to 15 parts of functional filler, 4 to 7 parts of pentaerythritol, 4 to 6 parts of foaming regulator, 15 to 17 parts of lubricant, and 1 to 3 parts of plasticization promoter; the functional filler is modified polystyrene-maleic anhydride modified fiber.

2. The multifunctional composite foaming agent for PVC soles according to claim 1, wherein, Each part of the modified rosin-based foaming agent includes the following components in parts by mass: 40 to 50 parts of foaming agent, 3 to 5 parts of foaming aid, 20 to 25 parts of stabilizer, 6 to 8 parts of foaming homogenizer, and 6 - 10 parts of urea; the foaming agent includes modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:(0.6 - 0.8).

3. A multifunctional composite foaming agent for PVC soles according to claim 2, characterized in that, The structure of the modified rosin is shown in Formula I Wherein R is an alkyl group having 18 to 22 carbon atoms.

4. A multifunctional composite foaming agent for PVC soles according to claim 1, characterized in that, The preparation method of the modified polystyrene-maleic anhydride modified fiber includes the following steps: A1. Mix maleic anhydride with thionyl chloride, dropwise add N,N-dimethylformamide, stir at room temperature for 9 - 10 h, add ice water to quench, and extract to obtain acid chloride maleic acid. A2. Mix the acid chloride maleic anhydride in step A1 with 1,3-propanediamine, add a solvent, cool down to 0 - 5 °C, add an acid-binding agent, stir at a constant temperature for 12 - 20 h, after the reaction is completed, concentrate and dry under reduced pressure, and obtain the compound shown in Formula VI by column chromatography. A3. Under an inert gas atmosphere, mix the compound shown in Formula VI in step A2 with 3,5-di-tert-butylsalicylaldehyde, add N,N-dimethylformamide, add potassium carbonate, heat up to 70 - 80 °C, stir at a constant temperature for 12 - 16 h, after the reaction is completed, cool down to room temperature, concentrate and dry under reduced pressure to obtain compound A. A4. Mix maleic anhydride with hydrotalcite, add ethanol, heat up to 60 - 70 °C, stir for 16 - 18 h, after the reaction is completed, filter and dry to obtain hydrotalcite grafted with modified maleic anhydride. A5. Mix compound A in step A3, hydrotalcite grafted with modified maleic anhydride in step A4, and styrene, add an initiator and 1,4-dioxane, introduce an inert protective gas, heat up to 60 - 70 °C, stir at a constant temperature for 1 - 2 h, after the reaction is completed, cool down to room temperature, add petroleum ether until no precipitation occurs, filter and dry to obtain modified polystyrene-maleic anhydride. A6. Mix modified polystyrene-maleic anhydride with glass fiber, add ethanol, heat up to 60 - 70 °C, stir for 16 - 18 h, after the reaction is completed, centrifuge and filter to obtain modified polystyrene-maleic anhydride modified fiber.

5. A multifunctional composite foaming agent for PVC soles according to claim 4, characterized in that, In step A2, the molar ratio of the acid chloride maleic anhydride to 1,3-propanediamine is 1:(2 - 2.2).

6. A multifunctional composite foaming agent for PVC soles according to claim 4, characterized in that, In step A3, the molar ratio of the compound shown in Formula VI, 3,5-di-tert-butylsalicylaldehyde, and potassium carbonate is 1:(2 - 2.2):(1.2 - 1.4).

7. A multifunctional composite foaming agent for PVC soles according to claim 4, characterized in that, In step A5, the mass ratio of compound A, hydrotalcite grafted with modified maleic anhydride, and styrene is 1:(1.5 - 1.7):(5 - 5.5).

8. A multifunctional composite foaming agent for PVC soles according to claim 1, characterized in that, The dispersant is one or more of high molecular wax, DY-222, and EP-316.

9. The multifunctional composite foaming agent for PVC soles according to claim 1, wherein, The foaming regulator is one or more of ZB-760, ZB-530, and HF530.

10. The preparation method of the multifunctional composite foaming agent for PVC soles according to any one of claims 1 to 9, characterized in that, It includes the following steps: Mix a modified rosin-based foaming agent, a dispersant, a functional filler, pentaerythritol, a foaming regulator, a lubricant, and a plasticization promoter evenly to obtain a multifunctional composite foaming agent for PVC soles.

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