Low-yellowing dibenzylidene sorbitol nucleating agent and preparation method thereof

Abstract

The invention provides a low-yellowing dibenzylidene sorbitol nucleating agent and a preparation method thereof, and relates to the technical field of nucleating agents. The low-yellowing dibenzylidene sorbitol nucleating agent is prepared from the following raw materials in parts by weight: 60 to 80 parts of dibenzylidene sorbitol, 8 to 12 parts of sodium diphenyl phosphate, 5 to 7 parts of aluminic acid ester coupling agent modified talcum powder, 4 to 8 parts of silicon dioxide, 3 to 5 parts of manganese oxide modified mica and 0.5 to 1 part of calcium stearate. The invention provides a low-yellowing dibenzylidene sorbitol nucleating agent and a preparation method thereof.The compound nucleating agent is composed of dibenzylidene sorbitol and an inorganic nucleating agent, the nucleating agent has good compatibility with dibenzylidene sorbitol and can be evenly dispersed in plastic to form an effective nucleating center, the crystallization process of the plastic is promoted, and the yellowing resistance of the plastic is improved. Through compounding, the nucleating property, the anti-yellowing property and the thermal stability of the plastic product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of nucleating agents, and in particular to a low-yellowing dibenzylidene sorbitol nucleating agent and a preparation method thereof. Background Art

[0002] In the plastic processing industry, nucleating agents, as an important functional additive, play a vital role in improving the crystallization properties of plastics, improving the physical and mechanical properties of products and processing performance. Among them, dibenzylidene sorbitol nucleating agents have become one of the most widely studied and applied nucleating agents due to their good compatibility with polyolefin plastics such as polypropylene (PP) and significant modification effects.

[0003] However, in practical applications, the existing dibenzylidene sorbitol nucleating agents often have certain impurities and unreacted products in the product due to limitations in raw material purity, reaction conditions and refining process during the preparation process. These impurities are prone to yellowing during the processing and storage of plastic products, affecting the appearance and service life of the products. In addition, traditional nucleating agents also have certain deficiencies in thermal stability and are difficult to meet the application requirements in high temperature environments.

[0004] Based on this, the present invention provides a low-yellowing dibenzylidene sorbitol nucleating agent and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a low-yellowing dibenzylidene sorbitol nucleating agent and a preparation method thereof, which can effectively improve the nucleating property, anti-yellowing property and thermal stability of plastics.

[0006] On the one hand, the present invention provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 60-80 parts of dibenzylidene sorbitol, 8-12 parts of sodium diphenyl phosphate, 5-7 parts of talc modified by an aluminate coupling agent, 4-8 parts of silicon dioxide, 3-5 parts of manganese oxide-modified mica, and 0.5-1 part of calcium stearate.

[0007] Further, the chemical formula of the dibenzylidene sorbitol is:

[0008]

[0009] wherein R1 and R2 are independently selected from CH3CH2CH2- or CH3CH2CH2O-; and wherein R3 is independently selected from -CH2CH2CH3 or -CH2-CH=CH2.

[0010] Furthermore, the preparation method of the aluminate coupling agent modified talc powder comprises: immersing the acid-treated talc powder in an aluminate coupling agent solution at a temperature of 100-110° C. for 5-6 hours, adding titanium dioxide, stirring at a speed of 250-270 r / min for 40-60 minutes, centrifuging, washing, and drying to obtain the talc powder.

[0011] Furthermore, the acid treatment step includes: immersing the talc in 40-50°C 40% nitric acid for 11-13 hours, washing with distilled water until neutral, drying at 90-100°C to constant weight, and then calcining at 240-260°C for 2-3 hours.

[0012] Furthermore, the weight ratio of aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is (3-5): (10-12): (2-4).

[0013] Furthermore, the weight ratio of the acid-treated talc powder, the aluminate coupling agent solution and titanium dioxide is (20-24): (60-80): (6-8).

[0014] Furthermore, the preparation method of the manganese oxide modified mica includes: adding mica pretreated with alkali and acid into deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 60-70°C, stirring for 120-140 minutes, washing after centrifugation, and drying at a temperature of 75-85°C for 10-12 hours.

[0015] Furthermore, the pretreatment step includes: adding the mica flakes to a 20% NaOH solution by mass, heating and stirring to soak for 50-60 minutes, then filtering and washing to pH = 7, then adding a 10% hydrochloric acid solution by mass, stirring and soaking for 60-70 minutes at room temperature, then filtering and washing to pH = 7, and drying at a temperature of 100°C for 5-6 hours.

[0016] Furthermore, the weight ratio of the pretreated mica, deionized water and manganese oxide is (3-4): (10-12): (1-2).

[0017] On the other hand, the present invention also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 300-400 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent modified talc, silicon dioxide, manganese oxide modified mica and calcium stearate, stirring at a temperature of 40-50°C for 3-4h and then cooling to room temperature to obtain the nucleating agent.

[0018] The beneficial effects of the present invention are:

[0019] The low-yellowing dibenzylidene sorbitol nucleating agent provided by the present invention uses dibenzylidene sorbitol as the main nucleating component to promote the crystallization process of plastics, improve the crystallization speed and crystallinity, and inorganic fillers such as modified talcum powder can absorb and disperse the heat generated by the plastics during processing and use, further improving the thermal stability of the plastics. At the same time, manganese oxide-modified mica is used to enhance the anti-yellowing performance of the plastics and improve the thermal stability.

[0020] The present invention utilizes manganese oxide modified mica as the "seed" of crystal nuclei. Mica itself has a certain layered structure. After being modified by manganese oxide, its surface properties and structure may change, which is more conducive to being used as a nucleation point in plastics. In the plastic processing process, the plastic molecular chains are promoted to be arranged in an orderly manner during the cooling process to form finer and more uniform crystal grains. These fine crystal grains can serve as additional nucleation points to increase the number of crystal nuclei in the plastic, thereby improving the crystallization rate and crystallinity of the plastic. Mica itself has a certain ultraviolet shielding performance, and the modification of manganese oxide further enhances this performance. When mica powder is added to plastics, its flaky structure can reflect, scatter or absorb ultraviolet rays, thereby reducing the destructive effect of ultraviolet rays on plastics and delaying the aging and yellowing process of plastics. In addition, manganese oxide modified mica may indirectly improve the anti-yellowing performance of plastics by improving their thermal stability. At high temperatures, plastics are prone to oxidation, degradation and other reactions, resulting in yellowing. The addition of manganese oxide modified mica can inhibit the occurrence of these reactions, thereby improving the thermal stability and heat resistance of plastics.

[0021] In the present invention, the aluminate coupling agent reacts with the surface of talc powder to bond with it by bonding force, participates in the polymerization reaction of the polymer to bond with the polymer by bonding force, so that the aluminate coupling agent combines the talc powder with the polymer, and the compatibility and dispersibility of the talc powder with the plastic matrix can be improved by modification of the aluminate coupling agent, thereby improving the nucleation performance of the plastic.

[0022] In addition, titanium dioxide is directly added during the talcum powder modification process, which can absorb and scatter ultraviolet rays, thereby reducing the destructive effect of ultraviolet rays on plastics and improving the anti-yellowing performance of plastics; the addition of aluminate coupling agents can not only improve the compatibility of talcum powder with plastic matrix, but also improve the stability of plastic molecules. By reducing the degradation and oxidation of plastic molecules during processing and use, aluminate coupling agents help maintain the original color and transparency of plastics, thereby further improving the anti-yellowing performance.

[0023] One end of the aluminate coupling agent can react with functional groups such as hydroxyl groups on the surface of talcum powder, and the other end can react with the plastic molecular chain to form a strong chemical bond. The formation of this chemical bond enhances the interfacial compatibility between talcum powder and the plastic matrix, making the talcum powder dispersed more evenly in the plastic, thereby more effectively serving as a heterogeneous nucleation point. In contrast, although the modification of silane coupling agent can also improve the compatibility of talcum powder with the plastic matrix, it mainly forms chemical bonds by reacting with the hydroxyl groups on the surface of talcum powder, and the reaction with the plastic molecular chain may not be as strong as that of aluminate coupling agent. In addition, talcum powder itself has a high thermal conductivity, which can accelerate the heat transfer inside the plastic. The aluminate coupling agent modified talcum powder is more evenly dispersed in the plastic, making the heat transfer more efficient, thereby reducing the degradation rate of the plastic at high temperature. The chemical bond between the aluminate coupling agent and the plastic molecular chain can enhance the interaction between the plastic molecular chains and improve the thermal stability of the plastic.

[0024] Aluminate coupling agent itself has certain antioxidant properties, which can slow down the degradation rate of plastic molecular chains during oxidation. This antioxidant property helps to extend the service life of plastics and reduce the yellowing phenomenon caused by oxidation. Although silane coupling agent can also improve the compatibility of talc and plastic matrix, its direct impact on antioxidant properties is relatively small. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The invention provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 60-80 parts of dibenzylidene sorbitol, 8-12 parts of sodium diphenyl phosphate, 5-7 parts of talc powder modified by an aluminate coupling agent, 4-8 parts of silicon dioxide, 3-5 parts of manganese oxide modified mica and 0.5-1 part of calcium stearate.

[0027] In a further embodiment, the chemical formula of the dibenzylidene sorbitol is:

[0028]

[0029] wherein R1 and R2 are independently selected from CH3CH2CH2- or CH3CH2CH2O-; and wherein R3 is independently selected from -CH2CH2CH3 or -CH2-CH=CH2.

[0030] In a further embodiment, the dibenzylidene sorbitol of the above structure can be prepared according to the prior art, such as invention patent CN101484458B.

[0031] In a further embodiment, the preparation method of the aluminate coupling agent modified talc powder includes: immersing the acid-treated talc powder in an aluminate coupling agent solution at a temperature of 100-110°C for 5-6 hours, adding titanium dioxide and stirring at a speed of 250-270r / min for 40-60 minutes, centrifuging, washing, and drying to obtain the talc powder.

[0032] In a further embodiment, the acid treatment step comprises: immersing the talc in 40-50°C 40% nitric acid for 11-13 hours, washing with distilled water until neutral, drying at 90-100°C to constant weight, and then calcining at 240-260°C for 2-3 hours.

[0033] In a further embodiment, the weight ratio of aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is (3-5): (10-12): (2-4).

[0034] In a further embodiment, the weight ratio of the acid-treated talc powder, the aluminate coupling agent solution and titanium dioxide is (20-24): (60-80): (6-8).

[0035] In a further embodiment, the preparation method of the manganese oxide modified mica includes: adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 60-70°C, stirring for 120-140 minutes, washing after centrifugation, and drying at a temperature of 75-85°C for 10-12 hours.

[0036] In a further embodiment, the pretreatment step includes: adding the mica flakes to a 20% NaOH solution by mass, heating and stirring to soak for 50-60 minutes, then filtering and washing to pH = 7, then adding a 10% hydrochloric acid solution by mass, stirring and soaking for 60-70 minutes at room temperature, then filtering and washing to pH = 7, and drying at a temperature of 100°C for 5-6 hours.

[0037] In a further embodiment, the weight ratio of the pretreated mica, deionized water and manganese oxide is (3-4): (10-12): (1-2).

[0038] The present invention also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 300-400 r / min, then sequentially adding sodium diphenyl phosphate, aluminate coupling agent modified talc, silicon dioxide, manganese oxide modified mica and calcium stearate, stirring at a temperature of 40-50° C. for 3-4 hours and then cooling to room temperature to obtain the nucleating agent.

[0039] The present invention is explained below with further examples. In the present invention, the aluminate coupling agent is DL-420, and the mica is purchased from Chuzhou Ge Rui Mining Co., Ltd.

[0040] Example 1

[0041] The present embodiment provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified with an aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0042] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0043] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0044] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours to obtain talc treated with acid; then immersing the talc treated with acid in an aluminate coupling agent solution at 105°C for 5.5 hours, adding titanium dioxide and stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the talc; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0045] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding the mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0046] This embodiment also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0047] Example 2

[0048] The present embodiment provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified with an aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0049] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0050] R1 is CH3CH2CH2- and R2 is CH3CH2CH2O-, and R3 is -CH2-CH=CH2.

[0051] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the product; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0052] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0053] This embodiment also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0054] Example 3

[0055] The present embodiment provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified with an aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0056] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0057] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0058] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the product; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0059] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0060] This embodiment also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0061] Example 4

[0062] The present embodiment provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified with an aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0063] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0064] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0065] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the product; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0066] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0067] This embodiment also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0068] Comparative Example 1

[0069] This comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of silane coupling agent modified talc, 6 parts of silicon dioxide, 4 parts of manganese oxide modified mica, and 0.75 parts of calcium stearate.

[0070] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0071] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0072] The preparation method of the silane coupling agent modified talc comprises: immersing the talc in 45°C nitric acid with a mass fraction of 40% for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in a silane coupling agent KH550 solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the talc; the weight ratio of the silane coupling agent KH550, anhydrous ethanol and water in the silane coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the silane coupling agent solution and titanium dioxide is 22:70:7.

[0073] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0074] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, silane coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0075] Comparative Example 2

[0076] This comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0077] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0078] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0079] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, then filtering, washing with water until pH=7, then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging and washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0080] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, talcum powder, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0081] Comparative Example 3

[0082] The present comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified with an aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0083] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0084] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0085] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in 45°C nitric acid with a mass fraction of 40% for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, and then stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the talc; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc to the aluminate coupling agent solution is 22:70.

[0086] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, filtering, washing with water until pH=7, and then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging, washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0087] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0088] Comparative Example 4

[0089] This comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of silicon dioxide, 4 parts of manganese oxide-modified mica, and 0.75 parts of calcium stearate.

[0090] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0091] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0092] The preparation method of manganese oxide modified mica comprises: adding mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 55 minutes, filtering, washing with water until pH=7, and then adding mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 65 minutes at room temperature, then filtering, washing with water until pH=7, and drying at a temperature of 100°C for 5.5 hours; adding mica pretreated with alkali and acid to deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 65°C, stirring for 130 minutes, centrifuging, washing with water, and drying at a temperature of 80°C for 11 hours; the weight ratio of the pretreated mica, deionized water and manganese oxide is 3.5:11:1.5.

[0093] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, silicon dioxide, manganese oxide-modified mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0094] Comparative Example 5

[0095] This comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified by aluminate coupling agent, 6 parts of silicon dioxide, 4 parts of mica, and 0.75 parts of calcium stearate.

[0096] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0097] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0098] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the product; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0099] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent-modified talc, silicon dioxide, mica and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0100] Comparative Example 6

[0101] This comparative example provides a low-yellowing dibenzylidene sorbitol nucleating agent, which is prepared from the following raw materials in parts by weight: 70 parts of dibenzylidene sorbitol, 10 parts of sodium diphenyl phosphate, 6 parts of talc modified by aluminate coupling agent, 6 parts of silicon dioxide, and 0.75 parts of calcium stearate.

[0102] Wherein, the chemical formula of the dibenzylidene sorbitol is:

[0103] R1 is CH3CH2CH2O- and R2 is CH3CH2CH2O-, and R3 is -CH2CH2CH3.

[0104] The preparation method of the aluminate coupling agent modified talc comprises: immersing the talc in nitric acid at 45°C and 40% by mass for 12 hours, washing with distilled water until neutral, drying at 95°C to constant weight, and then roasting at 250°C for 2.5 hours, immersing the acid-treated talc in an aluminate coupling agent solution, soaking at 105°C for 5.5 hours, adding titanium dioxide, stirring at a speed of 260r / min for 50 minutes, centrifuging, washing with water, and drying to obtain the product; the weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is 4:11:3; the weight ratio of the acid-treated talc, the aluminate coupling agent solution and titanium dioxide is 22:70:7.

[0105] This comparative example also provides a method for preparing a low-yellowing dibenzyl sorbitol nucleating agent, the steps comprising: adding dibenzyl sorbitol to a reaction container at a rotation speed of 350 r / min, and then sequentially adding sodium diphenyl phosphate, aluminate coupling agent modified talc, silicon dioxide and calcium stearate, stirring at 45° C. for 3.5 hours and then cooling to room temperature to obtain the nucleating agent.

[0106] Test example: The nucleating agent prepared in the above-mentioned Examples 1-4 and Comparative Examples 1-6 was extruded and granulated with polypropylene in a twin-screw extruder. The weight of the nucleating agent relative to the weight of the polypropylene was 0.1%, the melt extrusion temperature was 180°C, and the blend pellets were dried and made into samples on an injection molding machine, and the following tests were performed.

[0107] 1. Yellowing index test: refer to the X, Y, Z three stimulus values ​​of the sample tested by the Xrite / CE7000A spectrometer, and obtain the yellowing index A according to the method of GB2409-1980. Place the sample in an oven at 150°C for 500 hours. The difference in the yellowing index before and after the test is ΔA.

[0108] 2. Glossiness: Test the sample in an oven at 100°C for 200 hours according to ASTM standards;

[0109] 2. Heat deformation temperature test: refer to GB / T 1634-2004 test standard;

[0110] The test results are shown in Table 1.

[0111] Table 1 Test results

[0112] Yellowing index ΔA Glossiness Heat deformation temperature / ℃ Example 1 2.2 85 110 Example 2 2.5 84 108 Example 3 2.4 82 105 Example 4 2.5 84 106 Comparative Example 1 11.3 80 103 Comparative Example 2 27.9 76 99 Comparative Example 3 33.8 72 100 Comparative Example 4 40.1 63 96 Comparative Example 5 35.4 74 98 Comparative Example 6 46.2 66 95

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A low-yellowing dibenzylidene sorbitol nucleating agent, characterized in that: The invention is prepared from the following raw materials in parts by weight: 60-80 parts of dibenzylidene sorbitol, 8-12 parts of sodium diphenyl phosphate, 5-7 parts of talc powder modified by aluminate coupling agent, 4-8 parts of silicon dioxide, 3-5 parts of mica modified by manganese oxide, and 0.5-1 part of calcium stearate.

2. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 1, characterized in that: The chemical formula of the dibenzylidene sorbitol is: wherein R1 and R2 are independently selected from CH3CH2CH2- or CH3CH2CH2O-; and wherein R3 is independently selected from -CH2CH2CH3 or -CH2-CH=CH2.

3. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 1, characterized in that: The preparation method of the aluminate coupling agent modified talc comprises: immersing the acid-treated talc in an aluminate coupling agent solution at a temperature of 100-110° C. for 5-6 hours, adding titanium dioxide, stirring at a speed of 250-270 r / min for 40-60 minutes, centrifuging, washing and drying to obtain the talc.

4. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 3, characterized in that: The acid treatment step comprises: immersing talc in 40-50° C. 40% nitric acid for 11-13 hours, washing with distilled water until neutral, drying at 90-100° C. to constant weight, and then calcining at 240-260° C. for 2-3 hours.

5. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 3, characterized in that: The weight ratio of the aluminate coupling agent, anhydrous ethanol and water in the aluminate coupling agent solution is (3-5): (10-12): (2-4).

6. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 5, characterized in that: The weight ratio of the acid-treated talc powder, the aluminate coupling agent solution and titanium dioxide is (20-24): (60-80): (6-8).

7. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 1, characterized in that: The preparation method of manganese oxide modified mica comprises: adding mica pretreated with alkali and acid into deionized water to obtain a mica suspension, adding manganese oxide at a temperature of 60-70° C., stirring for 120-140 minutes, washing after centrifugation, and drying at a temperature of 75-85° C. for 10-12 hours.

8. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 1, characterized in that: The pretreatment step includes: adding the mica flakes to a 20% by mass NaOH solution, heating and stirring and soaking for 50-60 minutes, then filtering and washing until the pH value is 7, then adding the mica flakes to a 10% by mass hydrochloric acid solution, stirring and soaking for 60-70 minutes at room temperature, then filtering and washing until the pH value is 7, and drying at a temperature of 100°C for 5-6 hours.

9. The low-yellowing dibenzylidene sorbitol nucleating agent according to claim 1, characterized in that: The weight ratio of the pretreated mica, deionized water and manganese oxide is (3-4): (10-12): (1-2).

10. A method for preparing the low-yellowing dibenzylidene sorbitol nucleating agent according to any one of claims 1 to 9, characterized in that the steps include: At a rotation speed of 300-400 r / min, dibenzylidene sorbitol is added to the reaction container, followed by sodium diphenyl phosphate, aluminate coupling agent modified talc, silica, manganese oxide modified mica and calcium stearate. The mixture is stirred at 40-50°C for 3-4 hours and then cooled to room temperature.

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