Modified rosin-based foaming agent for PVC (polyvinyl chloride) soles and preparation method of modified rosin-based foaming agent

Abstract

The invention relates to the technical field of foaming materials, in particular to a modified rosin-based foaming agent for PVC soles and a preparation method thereof.The modified rosin-based foaming agent comprises, by mass, 40-50 parts of a foaming agent, 3-5 parts of an auxiliary foaming agent, 20-25 parts of a stabilizer, 6-8 parts of a foaming homogenizing agent and 6-10 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the modified rosin to the sodium bicarbonate microcapsules is 1: (0.6-0.8). The modified rosin-based foaming agent disclosed by the invention solves the problem that a rosin foaming agent cannot be directly used in a PVC (Polyvinyl Chloride) sole material, and meanwhile, the modified rosin-based foaming agent has a certain flame retardant property, and generated bubbles are compact and stable.

Description

Technical Field

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

[0002] PVC is a polar amorphous high polymer, which is widely used in various fields due to its light weight, chemical corrosion resistance, good electrical insulation and cost-effectiveness. In the shoe-making industry, PVC is widely used to manufacture soles because of its light weight, easy processing and low cost. PVC soles have good physical and chemical properties, such as wear resistance, good stability and durability.

[0003] However, at present, the weight of PVC soles is too heavy. In order to reduce the weight of the soles, a foaming agent has been developed for PVC soles to solve the problem of weight reduction. The common foaming methods include chemical foaming, physical foaming and surfactant foaming. Physical foaming can make the material have very small pores and low density, but physical foaming requires high equipment precision and great technical control difficulty, and the corresponding cost is also high; while chemical foaming has relatively low cost and is the most suitable method for making foamed soles. The common chemical foaming method is usually to directly add a chemical foaming agent to the material, and then produce polyvinyl chloride materials through injection molding or compression molding processes. However, for the injection molding process, it is difficult to control the foaming, that is, it is difficult to control the pore structure and pore density. Collapsed pores and merged pores often occur, and the pores are uneven. In recent years, people have been committed to the research of different surfactants. Surfactants have the function of changing the surface tension, which can well slow down the drainage speed inside the foam and increase the foam stability.

[0004] Rosin, as a commonly used material in the field of foaming agents, reacts with chemical reagents under specific conditions to produce a large number of uniform bubbles. These bubbles can significantly reduce the density of the material and improve its heat insulation performance, but it is often used in the field of building materials. For example, CN112266449A discloses "a preparation method of a plant-based building material foaming agent" using a foaming agent prepared from modified rosin and modified bone glue, with relatively comprehensive performance and good foam stability. Another example is CN101684047B discloses "foamed concrete" which consists of siliceous materials, calcareous materials, water and a composite foaming agent, and the composite foaming agent consists of a foam stabilizer fatty acid methanol amide and a rosin foaming agent. The foamed concrete prepared by this method is lighter in weight but higher in strength.

[0005] However, due to the differences in performance requirements between soles and concrete, the rosin foaming agent itself cannot be well applied to the sole foaming materials. In addition, the solubility of PVC and rosin is poor, so uniform and dense bubbles cannot be obtained.

[0006] Therefore, it is urgent to develop a modified rosin-based foaming agent that can be used for PVC sole foaming and has dense and stable bubbles. Summary of the Invention

[0007] The main object of the present invention is to provide a modified rosin-based foaming agent for PVC soles and its preparation method. This modified rosin-based foaming agent can avoid the situation that rosin foaming agents cannot be directly used in PVC sole materials. At the same time, this modified rosin-based foaming agent has certain flame retardant properties, and the generated bubbles are dense and stable.

[0008] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0009] On the one hand, the present invention provides a modified rosin-based foaming agent for PVC soles, which 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 this application, by using modified rosin and sodium bicarbonate microcapsules in combination, bubbles can be uniformly released during the preparation of PVC soles. By adjusting the mass ratio of modified rosin and sodium bicarbonate microcapsules, the bubbles can be made more stable. The reason may be that the modified rosin has a carboxyl group with strong acidity, which can react with sodium bicarbonate to generate carbon dioxide and release bubbles. In addition, the generated sodium carboxylate can make the modified rosin act as an anionic surfactant, thereby improving the stability of the foam. By adjusting the mass ratio of modified rosin and sodium bicarbonate microcapsules, there will be surplus modified rosin, which acts as a non-ionic surfactant and works together with the co-generated anionic surfactant to increase the density and stability of the bubbles.

[0011] In some embodiments, the modified rosin-based foaming agent for PVC soles further comprises the following components in parts by mass: 0.26 - 0.6 parts of heat stabilizer, 0.6 - 5.4 parts of anti-blocking agent, and 20 - 60 parts of impact modifier.

[0012] In some embodiments, the heat stabilizer is any one of zinc oxide, magnesium oxide, hydrotalcite, and SEBS.

[0013] In some embodiments, the impact modifier is a styrenic thermoplastic elastomer.

[0014] In some embodiments, each part of the anti-blocking agent is composed of 0.6 - 4 parts by mass of erucamide and 0.6 - 3 parts by mass of oleamide.

[0015] In some embodiments, the structure of the modified rosin is as shown in Formula I

[0016] Wherein R is an alkyl group with 18 to 22 carbon atoms.

[0017] The modified rosin of the present application has a balanced hydrophilic and hydrophobic property, has a certain surfactant effect, improves its dispersibility in PVC materials, and thus makes the generated bubbles more uniform. In addition, there is a halogen group with strong electron-withdrawing ability adjacent to the terminal carboxyl group of the modified rosin, which can assist in dispersing the negative charge on the carboxylate, thereby increasing the acidity of the carboxylic acid, enabling it to more easily undergo an acid-base neutralization reaction with sodium bicarbonate to generate carbon dioxide bubbles for foaming. At the same time, the generated sodium carboxylate can play the role of an anionic surfactant, cooperating with the excessive modified rosin to make the generated bubbles more uniform, stable, and dense. In addition, the applicant found that the modified rosin of the present application cooperates with sodium bicarbonate as the main foaming component and cooperates with other components to prepare a foaming agent for the preparation of PVC soles. The prepared PVC soles have good flame retardant properties. The reason may be that the modified rosin contains a large amount of halogen and nitrogen elements, which can increase the flame retardant resistance of the PVC sole material.

[0018] In some embodiments, the preparation method of the modified rosin includes the following steps:

[0019] 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 ends, 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, perform column chromatography to obtain the compound shown in Formula II

[0020]

[0021] S2. Mix the compound shown in Formula II in step S1 with R-Cl, add to a 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 ends, extract with ethyl acetate, combine the organic phases and concentrate under reduced pressure and dry to obtain the compound shown in Formula III

[0022]

[0023] S3. Dissolve the compound shown in Formula III in step S2 in a first solvent, add maleic acid and p-toluenesulfonic acid, heat up to 115 - 125 °C and stir at a constant temperature for 24 - 25 h. After the reaction ends, 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 10 - 15 times that of ethyl acetate to precipitate and dry to obtain the compound shown in Formula IV

[0024]

[0025] S4. Mix the compound shown in Formula IV in Step S1, isopropanolamine, concentrated sulfuric acid, and dichloromethane, heat up 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.

[0026]

[0027] S5. Mix the compound shown in Formula V in Step S4 and 2 - bromo - 5 - chlorobenzoic acid, add a second solvent, add an acid binding agent, heat up 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.

[0028] S6. Mix Compound A in Step S5 and R - Cl, add to a first solvent, add an acid binding agent, heat up 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.

[0029] In some embodiments, in Step S1, the molar ratio of abietic acid to isopropanolamine is 1:(1.1 - 1.3).

[0030] In some embodiments, in Step S1, the mass ratio of abietic acid to concentrated sulfuric acid is 1:(0.5 - 0.6).

[0031] In some embodiments, in Step S1, the mass - to - volume ratio of abietic acid to dichloromethane is 1:(8 - 10).

[0032] In some embodiments, in Step S2, the molar ratio of the compound shown in Formula II to R - Cl is 1:(2 - 2.2).

[0033] Preferably, in Step S2, the molar ratio of the compound shown in Formula II to R - Cl is 1:2.1.

[0034] In this application, by regulating the molar ratio of the compound shown in Formula II to R - Cl, the amino substitution can be made more complete, reducing the remaining raw materials and improving the yield.

[0035] In some embodiments, in Step S2, the first solvent is one or more of toluene, chloroform, ethyl acetate, and dichloromethane.

[0036] In some embodiments, in Step S2, the acid binding agent is one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0037] In some embodiments, in Step S2, the molar ratio of the acid binding agent to the compound shown in Formula II is (1.2 - 1.4):1.

[0038] In some embodiments, in step S3, the molar ratio of the compound shown in formula III to maleic acid is 1:(1 to 1.2).

[0039] In some embodiments, in step S3, the mass of p-toluenesulfonic acid is 0.2 to 0.4% of the total mass of the compound shown in formula III and maleic acid.

[0040] In some embodiments, in step S4, the molar ratio of the compound shown in formula IV to isopropanolamine is 1:(2 to 2.2).

[0041] Preferably, in step S4, the molar ratio of the compound shown in formula IV to isopropanolamine is 1:(2 to 2.2).

[0042] By regulating the molar ratio of the compound shown in formula IV to isopropanolamine in the present application, the esterification reaction can be made more complete, the amine group content can be increased, which lays a foundation for subsequent modification. In addition, the two active hydrogens in the amine group can provide more active sites and increase the group content.

[0043] In some embodiments, in step S5, the molar ratio of the compound shown in formula V to 2-bromo-5-chlorobenzoic acid is 1:(2.8 to 3).

[0044] Preferably, in step S5, the molar ratio of the compound shown in formula V to 2-bromo-5-chlorobenzoic acid is 1:(2.8 to 3).

[0045] By regulating the molar ratio of the compound shown in formula V to 2-bromo-5-chlorobenzoic acid in the present application, the active hydrogen in one side of the amine group can be retained, the hydrophobic and hydrophilic properties of the modified rosin can be balanced, and it can have a certain surfactant effect.

[0046] In some embodiments, in step S5, the second solvent is methanol or ethanol.

[0047] In some embodiments, in step S6, the molar ratio of compound A, R-Cl to the acid-binding agent is 1:(1 to 1.2):(1.2 to 1.4).

[0048] In some embodiments, the method for preparing the sodium bicarbonate microcapsules comprises the following steps:

[0049] (1) Dissolve sodium bicarbonate in water to obtain an aqueous phase;

[0050] (2) Dissolve polymethyl methacrylate in ethyl acetate, add a surfactant to obtain an oil phase;

[0051] (3) Mix the aqueous phase in step (1) with the oil phase in step (2), ultrasonically disperse for 10 to 20 min, and then stir in a homogenizing mixer to form a uniform and stable emulsion;

[0052] (4) Spray-dry the emulsion in step (3) at 60-80 °C to obtain sodium bicarbonate microcapsules.

[0053] In this application, by making sodium bicarbonate into microcapsules and blending them with modified rosin, it is possible to prevent the phenomenon that sodium bicarbonate directly reacts with modified rosin and causes non-foaming. The sodium bicarbonate microcapsules in this application need to be heated and foamed at high temperature during the preparation of PVC soles. At high temperature, the capsule wall of the microcapsules will rupture at high temperature to release sodium bicarbonate, and sodium bicarbonate reacts with modified rosin to release bubbles, achieving the foaming effect of PVC soles.

[0054] In some embodiments, the mass ratio of sodium bicarbonate to polymethyl methacrylate is 1:(1.2-3).

[0055] Preferably, the mass ratio of sodium bicarbonate to polymethyl methacrylate is 1:2.1.

[0056] In some embodiments, the co-foaming agent is one or more of P-533J, P-530A, P-531A, P-540J, P-551A, P-551J, and P560J.

[0057] In some embodiments, the stabilizer is a stearate.

[0058] In some embodiments, the stearate includes barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:(0.9-1.1):(0.9-1.1).

[0059] In some embodiments, the foaming homogenizer is any one of C5 petroleum resin, titanate coupling agent, ethylene bis-stearamide, and polyethylene wax.

[0060] On the other hand, the present invention provides a preparation method of a modified rosin-based foaming agent for PVC soles, including the following steps: Mix a co-foaming agent, a stabilizer, a foaming homogenizer, urea, a heat stabilizer, an anti-blocking agent, and an impact modifier to obtain a modified rosin-based foaming agent for PVC soles.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] (1) The modified rosin-based foaming agent for PVC soles of the present invention uses sodium bicarbonate microcapsules and modified rosin as the main foaming agent components, and is prepared by coordinating with a co-foaming agent, a stabilizer, a foaming homogenizer, and a foam promoter. The modified rosin-based foaming agent for PVC soles foams more uniformly, densely, and stably.

[0063] (2) The present invention regulates modified rosin and sodium bicarbonate microcapsules with a specific ratio, and the synergistic compounding of the two plays a foaming role. The reason may be that the carboxyl group with strong acidity in the modified rosin can react with sodium bicarbonate to produce carbon dioxide and release bubbles. In addition, the generated sodium carboxylate can make the modified rosin act as an anionic surfactant, thereby improving the stability of the foam. By regulating the mass ratio of the modified rosin and the sodium bicarbonate microcapsules, the modified rosin can remain in excess, acting as a non-ionic surfactant and synergistically with the generated anionic surfactant to jointly increase the density and stability of the bubbles.

[0064] (3) The modified rosin of the present invention has good dispersibility in the PVC material. At the same time, halogen groups with strong electron-withdrawing ability exist in the ortho position of the terminal carboxyl group of the modified rosin, which can assist in dispersing the negative charge on the carboxylate, thereby increasing the acidity of the carboxylic acid and making it easier to undergo an acid-base neutralization reaction with sodium bicarbonate.

[0065] (4) The present invention makes sodium bicarbonate into microcapsules to prevent the phenomenon that sodium bicarbonate directly acts on the modified rosin and reacts, resulting in the inability to foam. In addition, the sodium bicarbonate microcapsules need to be heated at high temperature for foaming during the preparation process of the PVC sole. At high temperature, the capsule wall of the microcapsule will rupture at high temperature to release sodium bicarbonate, and sodium bicarbonate reacts with the modified rosin to release bubbles to achieve the foaming effect of the PVC sole. Description of the Drawings

[0066] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum of the modified rosin prepared in Preparation Example 1 of the present invention. Detailed Embodiments

[0067] 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 used to illustrate the present invention, and not used to limit the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0068] In the following preparation examples and examples, the styrene-based thermoplastic elastomer is purchased from Guangzhou Situlai Chemical Co., Ltd.; polymethyl methacrylate is purchased from Dongguan Changping Senhai Plastic Trade Co., Ltd.; the titanate coupling agent is purchased from Shandong Huian Chemical Co., Ltd.

[0069] Preparation Example 1

[0070] The preparation method of the modified rosin includes the following steps:

[0071] 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 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 and adjust the pH of the system to 6 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 II.

[0072]

[0073] S2. Mix 0.1 mol of the compound shown in Formula II from step S1 with 0.21 mol of octadecyl chloride, add them to 330 mL 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, extract with chloroform, combine the organic phases, and concentrate and dry under reduced pressure to obtain the compound shown in Formula III.

[0074] wherein R is a C18 alkyl group;

[0075] S3. Dissolve 0.1 mol of the compound shown in Formula III from step S2 in 630 mL of chloroform, add 0.11 mol of maleic acid and 0.2 g of p-toluenesulfonic acid, heat the mixture to 120 °C and stir it 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.

[0076]

[0077] S4. Mix 0.1 mol of the compound shown in Formula IV from step S1 with 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 and 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.

[0078]

[0079] S5. Mix 0.1 mol of the compound shown in Formula V from step S4 with 0.29 mol of 2-bromo-5-chlorobenzoic acid, add them to 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 under reduced pressure to obtain Compound A.

[0080] S6. Mix 0.1 mol of compound A in step S5 with 0.11 mol of octadecyl chloride, add them to 1.5 L 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, concentrate under reduced pressure and dry to obtain the compound shown in formula I, which is the modified rosin.

[0081] Wherein R is a C18 alkyl group.

[0082] NMR spectrum analysis of modified rosin: δ 7.85 (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 in 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 in 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 in 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 in 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 in 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 on 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 connection 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 in the following 16), 1.76 - 1.39 (m, 16H), 1.38 - 1.21 (m, 88H, and the previous 16H all come from the carbon chain, six-membered ring 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).

[0083] Preparation Example 2

[0084] The preparation method of modified rosin, the specific implementation manner is the same as that of Preparation Example 1, the difference is that 1-chloroheptane in an equimolar amount is used instead of octadecyl chloride in step S2.

[0085] Preparation Example 3

[0086] The preparation method of modified rosin, the specific implementation manner is the same as that of Preparation Example 1, the difference is that 4-chloropropionic acid in an equimolar amount is used instead of 2-bromo-5-chlorobenzoic acid.

[0087] Preparation Example 4

[0088] The preparation method of modified rosin, the specific implementation manner is the same as that of Preparation Example 1, the difference is that the addition amount of 2-bromo-5-chlorobenzoic acid is 0.4 mol.

[0089] Preparation Example 5

[0090] The preparation method of sodium bicarbonate microcapsules comprises the following steps:

[0091] (1) Dissolve 10 g of sodium bicarbonate in 110 mL of water to obtain an aqueous phase;

[0092] (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;

[0093] (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;

[0094] (4) Spray-dry the emulsion in step (3) at 70 °C to obtain sodium bicarbonate microcapsules.

[0095] Example 1

[0096] A modified rosin-based foaming agent for PVC soles, comprising 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.

[0097] Among them, the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsules are prepared from Preparation Example 5, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:1:1.

[0098] Preparation method of modified rosin-based foaming agent for PVC soles, comprising the following steps: Mix a foaming agent, P-533J, a stabilizer, a titanate coupling agent, and urea to obtain the modified rosin-based foaming agent for PVC soles.

[0099] Example 2

[0100] A modified rosin-based foaming agent for PVC soles, comprising the following components in parts by mass: 40 parts of a foaming agent, 3 parts of P-533J, 20 parts of a stabilizer, 6 parts of a titanate coupling agent, and 6 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.6.

[0101] Among them, the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsules are prepared from Preparation Example 5, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:0.9:0.9.

[0102] Preparation method of modified rosin-based foaming agent for PVC soles, comprising the following steps: Mix a foaming agent, P-533J, a stabilizer, a titanate coupling agent, and urea to obtain the modified rosin-based foaming agent for PVC soles.

[0103] Example 3

[0104] A modified rosin-based foaming agent for PVC soles, comprising the following components in parts by mass: 50 parts of a foaming agent, 5 parts of P-533J, 25 parts of a stabilizer, 8 parts of a titanate coupling agent, and 10 parts of urea; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.8.

[0105] Among them, the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsules are prepared from Preparation Example 5, and the stabilizer comprises barium stearate, calcium stearate, and zinc stearate with a mass ratio of 1:1.1:1.1.

[0106] Preparation method of modified rosin-based foaming agent for PVC soles, comprising the following steps: Mix a foaming agent, P-533J, a stabilizer, a titanate coupling agent, and urea to obtain the modified rosin-based foaming agent for PVC soles.

[0107] Example 4

[0108] A modified rosin-based foaming agent for PVC soles, comprising 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, 8 parts of urea, 0.4 part of zinc oxide, 3 parts of a styrenic thermoplastic elastomer, and 35 parts of an anti-adhesive; the foaming agent comprises modified rosin and sodium bicarbonate microcapsules, and the mass ratio of the two is 1:0.7.

[0109] Among them, the modified rosin is prepared from Preparation Example 1, the sodium bicarbonate microcapsule is prepared from Preparation Example 5, the stabilizer includes barium stearate, calcium stearate and zinc stearate with a mass ratio of 1:1:1, and each portion of the anti-adhesive agent is composed of 2.5 parts of erucamide and 1.5 parts of oleamide.

[0110] A preparation method of a modified rosin-based foaming agent for PVC soles comprises the following steps: mixing a foaming agent, P-533J, a stabilizer, a titanate coupling agent, urea, zinc oxide, a styrenic thermoplastic elastomer and an anti-adhesive agent to obtain the modified rosin-based foaming agent for PVC soles.

[0111] Example 5

[0112] A modified rosin-based 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 rosin is prepared from Preparation Example 2.

[0113] Example 6

[0114] A modified rosin-based 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 rosin is prepared from Preparation Example 3.

[0115] Example 7

[0116] A modified rosin-based 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 rosin is prepared from Preparation Example 4.

[0117] Example 8

[0118] A modified rosin-based 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 compound shown in Formula IV is used to replace the modified rosin.

[0119] Comparative Example 1

[0120] A modified rosin-based 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 an equal mass portion of sodium bicarbonate is used to replace the sodium bicarbonate microcapsule.

[0121] Comparative Example 2

[0122] A modified rosin-based 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 an equal mass portion of rosin is used to replace the modified rosin.

[0123] Performance test:

[0124] By mass, 60 parts of PVC and 1 part of a modified rosin-based foaming agent for PVC soles are mixed, added to a high-speed mixer and stirred thoroughly for 10 minutes. After 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 foaming is completed, the sheet is taken out and cooled sufficiently. After cooling, the sheet is put on a molding machine for secondary molding, and then trimmed and edge-cut to obtain the PVC sole material.

[0125] (1) Foaming density test: The average density of the PVC sole material is measured using a foam density tester.

[0126] (2) Foaming stability test: According to the test standard ASTM D-792, the specific gravity of 20 PVC sole materials prepared in each example and comparative example is tested, and the variance is calculated. The larger the variance, the worse the stability, and vice versa.

[0127] (3) Flame retardancy: The flame retardancy of the PVC sole material is tested and classified according to the UL94 standard.

[0128] The PVC sole materials prepared in each example and comparative example are tested according to the above test methods, and the results are shown in Table 1.

[0129] Table 1

[0130] <![CDATA[Average density (kg / m 3 )]]> Variance UL94 Rating Example 1 63.5 0.00135 V-0 Example 2 62.3 0.00139 V-0 Example 3 63.2 0.00136 V-0 Example 4 65.3 0.00128 V-0 Example 5 62.7 0.00158 V-0 Example 6 58.2 0.00140 V-0 Example 7 62.9 0.00159 V-0 Example 8 57.9 0.00138 V-1 Comparative Example 1 45.2 0.00142 V-0 Comparative Example 2 55.2 0.00192 V-2

[0131] According to the data analysis in Table 1, it can be seen that the foaming agents in Examples 1 to 4 have a high foaming density and good stability, and the prepared PVC sole materials have good flame retardant properties; in Example 5, since equimolar 1-chloroheptane is used instead of octadecyl chloride, the surface activity effect of the modified rosin is weakened, resulting in a decrease in the foaming stability of the foaming agent; in Example 6, since equimolar 4-chloropropionic acid is used instead of 2-bromo-5-chlorobenzoic acid, the carboxyl group has poor acidity and is not easy to react with sodium bicarbonate. However, due to the increase in temperature, sodium bicarbonate will still generate a part of carbon dioxide, but its foaming effect is weak, resulting in a decrease in the foaming density; in Example 7, since the molar ratio of 2-bromo-5-chlorobenzoic acid to the compound shown in Formula V is changed, the hydrophobic and hydrophilic properties of the modified rosin are unbalanced, and the surface activity effect becomes poor, resulting in a decrease in the foaming stability of the foaming agent; in Example 8, since the compound shown in Formula IV is used instead of the modified rosin, the weak acidity of the carboxyl group leads to a decrease in the foaming density of the foaming agent. At the same time, since it does not contain halogen and the nitrogen element content decreases, the flame retardant property of the PVC sole material decreases; in Comparative Example 1, since equimass sodium bicarbonate is used instead of sodium bicarbonate microcapsules, sodium bicarbonate directly acts on the modified rosin, and a large amount of sodium bicarbonate is consumed, resulting in poor foaming effect and decreased density; in Comparative Example 2, since equimass rosin is used instead of the modified rosin, the solubility of rosin and PVC is poor. At the same time, rosin does not have a surface activity effect, resulting in poor foaming stability of the foaming agent. In addition, the reaction efficiency of rosin and sodium bicarbonate is low, resulting in a decrease in the foaming density. Moreover, the foaming agent does not contain nitrogen element and halogen, resulting in a decrease in the flame retardant effect of the prepared PVC sole material.

[0132] 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. However, these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A modified rosin-based foaming agent for PVC soles, characterized in that, It comprises the following components in parts by mass: 40 to 50 parts of a foaming agent, 3 to 5 parts of a co-foaming agent, 20 to 25 parts of a stabilizer, 6 to 8 parts of a 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).

2. The modified rosin-based foaming agent for PVC soles according to claim 1, wherein The modified rosin-based foaming agent for PVC soles further comprises the following components in parts by mass: 0.26 to 0.6 parts of a heat stabilizer, 0.6 to 5.4 parts of an anti-blocking agent, and 20 to 60 parts of an impact modifier.

3. The modified rosin-based foaming agent for PVC sole according to claim 2, characterized in that, The co-foaming agent is one or more of P-533J, P-530A, P-531A, P-540J, P-551A, P-551J, and P560J.

4. The modified rosin-based blowing agent for PVC soles according to claim 2, wherein, The structure of the modified rosin is shown in Formula I Wherein R is an alkyl group having 18 to 22 carbon atoms.

5. The modified rosin-based foaming agent for PVC soles according to claim 3, characterized in that, The preparation method of the modified rosin comprises the following steps: S1. Mix abietic acid with 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, and then perform column chromatography to obtain the compound shown in Formula II S2. Mix the compound shown in Formula II in step S1 with R-Cl, add to the 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, extract with ethyl acetate, combine the organic phases, concentrate under reduced pressure and dry to obtain the compound shown in Formula III S3. Dissolve the compound shown in Formula III in step S2 in the 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 S4. Mix the compound shown in Formula IV in step S1 with 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, and then perform column chromatography to obtain the compound shown in Formula V S5. Mix the compound shown in Formula V in step S4 with 2-bromo-5-chlorobenzoic acid, add to the 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; S6. Mix compound A in step S5 with R-Cl, add to the 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.

6. The modified rosin-based foaming agent for PVC sole according to claim 4, wherein, In step S2, the molar ratio of the compound shown in Formula II to R-Cl is 1:(2 - 2.2).

7. A modified rosin-based foaming agent for PVC soles according to claim 4, characterized in that, In step S5, the molar ratio of the compound shown in Formula V to 2-bromo-5-chlorobenzoic acid is 1:(2.8 - 3).

8. The modified rosin-based foaming agent for PVC soles according to claim 2, characterized in that, The preparation method of the sodium bicarbonate microcapsules comprises the following steps: (1) Dissolve sodium bicarbonate in water to prepare an aqueous phase; (2) Dissolve polymethyl methacrylate in ethyl acetate, add a surfactant to prepare an oil phase; (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 an emulsion; (4) Spray-dry the emulsion in step (3) at 60 - 80 °C to obtain sodium bicarbonate microcapsules.

9. The modified rosin-based blowing agent for PVC sole according to claim 8, characterized in that, The mass ratio of the sodium bicarbonate to polymethyl methacrylate is 1:(1.2 - 3).

10. A preparation method of the modified rosin-based foaming agent for PVC soles according to any one of claims 2 to 9, characterized in that, It includes the following steps: Mix a co-foaming agent, a stabilizer, a foaming homogenizer, urea, a heat stabilizer, an anti-caking agent, and an impact modifier to obtain a modified rosin-based foaming agent for PVC soles.

Images