Application method of lead-zinc-based heat stabilizer master batch

Abstract

The invention relates to the technical field of polyvinyl chloride heat stabilizers, and particularly discloses a use method of a lead-zinc-based heat stabilizer master batch. The preparation processes of synthesis of intermediate raw materials and granulation, tabletting, powder preparation and the like of composite heat stabilizers are omitted, original materials of existing lead-zinc-based heat stabilizers are directly used for preparing polyvinyl chloride plastic products, the kneading temperature, heating section heat energy and molecular shear heat energy of mixed materials during plastic processing are utilized, and the heat stability of the polyvinyl chloride plastic products is improved. The lead-zinc-based heat stabilizer master batch is added to promote the synthesis of each monomer in the lead-zinc-based heat stabilizer master batch, and participates in absorbing chloride ions and hydrogen ions decomposed in the processing of polyvinyl chloride plastic products while synthesizing in a molten state, so that the formation of hydrogen chloride is prevented, the degradation of polyvinyl chloride is prevented, and the smooth molding of the polyvinyl chloride plastic products is realized. The production efficiency is remarkably improved, the purposes of saving energy, protecting the environment and reducing the energy consumption are achieved, the production cost is greatly reduced, and the thermal stability effect of the polyvinyl chloride plastic product is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of polyvinyl chloride heat stabilizers, and in particular to a method for using a lead-zinc-based heat stabilizer masterbatch. Background Art

[0002] Polyvinyl chloride (PVC) is one of the five major general-purpose plastics, second only to polyethylene (PE) and polypropylene (PP). It has the advantages of high strength, corrosion resistance, difficulty in burning, good insulation and transparency. Its products are widely used in construction, chemical, electrical appliances, daily necessities, packaging and other industries. Polyvinyl chloride and vinyl chloride copolymers are heat-sensitive resins. They are very easy to release hydrogen chloride during heat processing, which in turn triggers thermal aging degradation reactions. Heat stabilizers are one of the key basic materials in the entire plastic industry, especially the PVC industry. They are an indispensable type of additives in the processing of polymer materials. They can not only prevent the degradation of polymer materials caused by heat or mechanical shearing during the processing process, but also avoid the destructive effects of heat, light and oxygen during the long-term use of the products. Heat stabilizers generally achieve the purpose of heat stabilization by absorbing hydrogen chloride, replacing active chlorine and double bond addition. The types of heat stabilizers widely used in industry generally include lead-based, zinc-based, lead-zinc-based composites and organic tin. The function of a single-component heat stabilizer is relatively simple, and it is difficult to achieve effective heat stabilization for polyvinyl chloride. Therefore, the most commonly used are composite heat stabilizers.

[0003] At present, the method of using composite heat stabilizers is to first synthesize the monomer raw materials of each stabilizer into intermediate raw materials (such as zinc stearate, calcium stearate, lead stearate, etc.), then melt the intermediate raw materials at high temperature (100℃~150℃), cold press molding, and obtain composite heat stabilizers, and then heat the composite heat stabilizers and plastics together (160℃~230℃) to exert the stabilizing effect of the heat stabilizer on the plastic. The synthesis of intermediate raw materials and the preparation process of composite heat stabilizers require a lot of manpower, water and electricity, high energy consumption, and multiple pollution to the environment. Therefore, there is an urgent need to find a method for using composite stabilizers that can reduce energy consumption and improve the thermal stability of polyvinyl chloride. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for using a lead-zinc-based heat stabilizer masterbatch, in which the lead-zinc-based heat stabilizer masterbatch is directly subjected to a thermal reaction with a polyvinyl chloride raw material to form a corresponding plastic product, thereby omitting the synthesis of intermediate raw materials and the preparation processes of granulation, tabletting, and powder making of the composite heat stabilizer, thereby greatly reducing the production cost and improving the thermal stability of the polyvinyl chloride plastic product.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: A method for using a lead-zinc-based heat stabilizer masterbatch comprises the following steps: The lead-zinc-based heat stabilizer masterbatch is added to the polyvinyl chloride raw material, and the obtained mixture is formed through a molding process to obtain a polyvinyl chloride plastic product; The components of the lead-zinc-based heat stabilizer masterbatch include zinc oxide, lead oxide, calcium hydroxide and stearic acid; the lead-zinc-based heat stabilizer masterbatch is prepared by physically mixing the components.

[0006] Compared with the prior art, the method for using the lead-zinc-based heat stabilizer masterbatch provided by the present invention omits the synthesis of intermediate raw materials and the preparation processes of granulation, tableting, powder making, etc. of the composite heat stabilizer, and directly uses the original materials of the existing lead-zinc-based heat stabilizer (i.e., the components of the lead-zinc-based heat stabilizer masterbatch, and the monomer raw materials are not given any conditions for reaction) for the preparation of polyvinyl chloride plastic products, and utilizes the kneading temperature of the mixed material during plastic processing, the heat energy of the heating section, and the molecular shear heat energy to promote the synthesis of the monomers in the lead-zinc-based heat stabilizer masterbatch, and in the molten state, the monomers are synthesized while participating in the absorption of Cl decomposed in the processing of polyvinyl chloride plastic products. - With H + , to prevent the formation of hydrogen chloride, accordingly, Pb 2+ 、Zn 2+ Plasma bonding in the corresponding dechlorination - , H + On the broken carbon chain, it prevents the carbon chain from breaking to form a conjugated double bond, Pb 2+ It plays the role of absorbing hydrogen chloride, Zn 2+ It replaces the Cl on the propylene group - It can prevent the degradation of polyvinyl chloride plastic products and thus realize the smooth molding of polyvinyl chloride plastic products.

[0007] The method for using the lead-zinc-based heat stabilizer masterbatch provided by the present invention not only significantly improves production efficiency, but also achieves the purpose of energy conservation and environmental protection, reduces energy consumption, greatly reduces production costs, and effectively improves the thermal stability of polyvinyl chloride plastic products. The prepared polyvinyl chloride plastic products have good color stability and heat resistance, and can be used in products such as drainage pipes, water supply pipes, profiles, wires and cables, foamed plates, resin tiles, and injection molded pipe products, thereby enhancing the market competitiveness of the products.

[0008] Preferably, the components of the lead-zinc-based heat stabilizer masterbatch also include at least two of tribasic lead sulfate, calcium carbonate, PE wax, paraffin or additives.

[0009] Further preferably, the auxiliary agent includes at least one of an antioxidant, uracil, polyol, hydrotalcite, zeolite, magnesium oxide, bisphenol A, phosphite, calcium acetylacetonate, epoxy soybean oil or dipentaerythritol.

[0010] Preferably, the components of the lead-zinc-based heat stabilizer masterbatch include, by weight: 15 to 25 parts of zinc oxide, 320 to 370 parts of lead oxide, 30 to 60 parts of calcium hydroxide and 1800 to 2100 parts of stearic acid.

[0011] Further preferably, the components of the lead-zinc-based heat stabilizer masterbatch include, by weight: 15 to 20 parts of zinc oxide, 330 to 370 parts of lead oxide, 35 to 55 parts of calcium hydroxide, 1900 to 2000 parts of stearic acid, 900 to 1100 parts of tribasic lead sulfate, 1000 to 1450 parts of calcium carbonate, 0 to 500 parts of PE wax, 0 to 500 parts of paraffin and 0 to 650 parts of additives.

[0012] In the present invention, the specific dosage of each component of the lead-zinc-based heat stabilizer masterbatch can be designed by reversely deducing the dosage of the monomer raw materials (such as zinc oxide, lead oxide, calcium hydroxide, stearic acid, etc.) used according to the dosage of the existing intermediate raw materials of the lead-zinc-based heat stabilizer (needing to be chemically synthesized, such as tin stearate, calcium stearate, lead stearate, etc.), so that the downstream PVC product manufacturers only need to use the existing lead-zinc-based stabilizer in the dosage.

[0013] Preferably, the preparation method of the lead-zinc based heat stabilizer masterbatch comprises: mixing the components of the lead-zinc based heat stabilizer masterbatch for 30 min to 50 min to obtain the lead-zinc based heat stabilizer masterbatch.

[0014] Preferably, the mass ratio of the lead-zinc based heat stabilizer masterbatch to the polyvinyl chloride raw material is (2-4):100.

[0015] The present invention does not limit the specific components of the polyvinyl chloride raw material, and the conventional components and amounts in the art can be used. For example, the polyvinyl chloride raw material includes polyvinyl chloride resin powder, pigments and fillers, and modifiers; the pigments and fillers include titanium dioxide and calcium carbonate, and the modifier includes ACR (copolymer of methyl methacrylate and acrylate).

[0016] Preferably, the mixture further comprises at least one of a plasticizer or a chelating agent.

[0017] Further preferably, the plasticizer includes at least one of dioctyl ester or dibutyl ester.

[0018] Further preferably, the chelating agent comprises phosphite.

[0019] More preferably, the chelating agent includes at least one of triphenyl phosphite or monophenyl phosphite.

[0020] Further preferably, the mass ratio of the plasticizer to the lead-zinc based heat stabilizer masterbatch is (0-5):100.

[0021] Further preferably, the mass ratio of the chelating agent to the lead-zinc-based heat stabilizer masterbatch is (0-5):100.

[0022] Preferably, the molding process includes extrusion molding, calendering molding or injection molding.

[0023] Preferably, the molding temperature is 160°C to 230°C, more preferably 180°C to 210°C, and even more preferably 190°C to 200°C.

[0024] The present invention does not limit the specific molding time of the molding process, and conventional operations in the art may be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a comparison diagram of the dynamic processability of the mixed material during the rheological process of Example 1 of the present invention and Comparative Example 1; Figure 2 It is a comparison diagram of the dynamic processability of the mixed material during the rheological process of Example 2 of the present invention and Comparative Example 2; Figure 3 It is a comparison diagram of the dynamic processability of the mixed material during the rheological process of Example 3 of the present invention and Comparative Example 3; Figure 4 It is a comparison diagram of the dynamic processability of the mixed material during the rheological process of Example 4 of the present invention and Comparative Example 4; Figure 5 These are test pictures of polyvinyl chloride plastic products prepared in Examples 1 to 4 of the present invention and Comparative Examples 1 to 4 at different heat aging times. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] In the present invention, materials not specifically described are all commercially available products. In the embodiment of the present invention, the polyvinyl chloride raw material is composed of titanium dioxide, ACR, calcium carbonate and polyvinyl chloride resin powder in a mass ratio of 1:1.5:19:62.5.

[0028] Example 1 This embodiment provides a method for using a lead-zinc-based heat stabilizer masterbatch, comprising the following steps: S1, weigh 15 parts of zinc oxide, 340 parts of lead oxide, 45 parts of calcium hydroxide, 1900 parts of stearic acid, 1000 parts of tribasic lead sulfate, 1400 parts of calcium carbonate and 400 parts of PE wax (a total of 5100 parts), mix the components by mechanical stirring for 40 minutes to obtain a lead-zinc based heat stabilizer masterbatch.

[0029] S2, add the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material, the mass ratio of the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material is 3:100, and extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain a polyvinyl chloride plastic product. The performance test diagram of the mixed material during the rheological process is shown in the figure below Figure 1 shown.

[0030] Example 2 This embodiment provides a method for using a lead-zinc-based heat stabilizer masterbatch, comprising the following steps: S1, weigh 15 parts of zinc oxide, 330 parts of lead oxide, 35 parts of calcium hydroxide, 1900 parts of stearic acid, 900 parts of tribasic lead sulfate, 1270 parts of calcium carbonate, 350 parts of PE wax, 100 parts of hydrotalcite, 50 parts of epoxidized soybean oil and 50 parts of calcium acetone (a total of 5000 parts), mix the components by mechanical stirring for 40 minutes to obtain a lead-zinc based heat stabilizer masterbatch.

[0031] S2, add lead-zinc-based heat stabilizer masterbatch and dioctyl ester to polyvinyl chloride raw materials, the mass ratio of lead-zinc-based heat stabilizer masterbatch, dioctyl ester and polyvinyl chloride raw materials is 2:0.08:100, extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain polyvinyl chloride plastic products. The performance test diagram of the mixed material during the rheological process is as follows Figure 2 shown.

[0032] Example 3 This embodiment provides a method for using a lead-zinc-based heat stabilizer masterbatch, comprising the following steps: S1, weigh 20 parts of zinc oxide, 370 parts of lead oxide, 55 parts of calcium hydroxide, 2000 parts of stearic acid, 1100 parts of tribasic lead sulfate, 1000 parts of calcium carbonate, 450 parts of paraffin, 200 parts of hydrotalcite, 200 parts of zeolite and 200 parts of polyol (a total of 5595 parts), mix the components by mechanical stirring for 40 minutes to obtain a lead-zinc based heat stabilizer masterbatch.

[0033] S2, add lead-zinc-based heat stabilizer masterbatch and triphenyl phosphite to polyvinyl chloride raw materials, the mass ratio of lead-zinc-based heat stabilizer masterbatch, triphenyl phosphite and polyvinyl chloride raw materials is 4:0.04:100, extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain polyvinyl chloride plastic products. The performance test diagram of the mixed material during the rheological process is as follows Figure 3 shown.

[0034] Example 4 This embodiment provides a method for using a lead-zinc-based heat stabilizer masterbatch, comprising the following steps: S1, weigh 25 parts of zinc oxide, 350 parts of lead oxide, 45 parts of calcium hydroxide, 1880 parts of stearic acid, 1000 parts of tribasic lead sulfate, 1400 parts of calcium carbonate, 350 parts of PE wax, 100 parts of paraffin wax, 100 parts of antioxidant, 100 parts of phosphite and 400 parts of zeolite (a total of 5750 parts), mix the components by mechanical stirring for 40 minutes to obtain a lead-zinc based heat stabilizer masterbatch.

[0035] S2, add the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material, the mass ratio of the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material is 3:100, and extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain a polyvinyl chloride plastic product. The performance test diagram of the mixed material during the rheological process is shown in the figure below Figure 4 shown.

[0036] Comparative Example 1 This comparative example provides a method for preparing a polyvinyl chloride plastic product, firstly using a lead-zinc-based heat stabilizer in a corresponding amount as in Example 1, and then preparing the polyvinyl chloride plastic product by using the lead-zinc-based heat stabilizer, specifically comprising the following steps: S1, weigh 350 parts of calcium stearate, 125 parts of zinc stearate, 1175 parts of lead stearate, 650 parts of stearic acid, 1000 parts of tribasic lead sulfate, 1400 parts of calcium carbonate and 400 parts of PE wax (a total of 5100 parts), melt-mix the raw materials at 110°C for 2h to obtain a lead-zinc based heat stabilizer.

[0037] Among them, calcium stearate is prepared by heating stearic acid and calcium hydroxide, zinc stearate is prepared by heating stearic acid and zinc oxide, and lead stearate is prepared by heating stearic acid and lead oxide. The reaction equation is as follows: 2C 17 H 35 COOH+Ca(OH) 2 =(C 17 H 35 COO 2 Ca + 2H 2 O 2C 17 H 35 COOH+ZnO=(C 17 H 35 COO 2 Zn+H 2 O 2C 17 H 35 COOH+PbO=(C 17 H 35 COO 2 Pb+H 2 O S2, add the lead-zinc-based heat stabilizer to the polyvinyl chloride raw material, the mass ratio of the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material is 3:100, and extrude the obtained mixture through a rheometer at 190°C, cool it to room temperature, and obtain a polyvinyl chloride plastic product. The performance test diagram of the mixed material during the rheological process is as follows Figure 1 shown.

[0038] Comparative Example 2 This comparative example provides a method for preparing a polyvinyl chloride plastic product, firstly using a lead-zinc-based heat stabilizer in a corresponding amount as in Example 2, and then preparing the polyvinyl chloride plastic product by using the lead-zinc-based heat stabilizer, specifically comprising the following steps: S1, weigh 265 parts of calcium stearate, 100 parts of zinc stearate, 825 parts of lead stearate, 1090 parts of stearic acid, 900 parts of tribasic lead sulfate, 1270 parts of calcium carbonate, 350 parts of PE wax, 100 parts of hydrotalcite, 50 parts of epoxidized soybean oil and 50 parts of calcium acetone (a total of 5000 parts), melt-mix the raw materials at 110°C for 2h to obtain a lead-zinc based heat stabilizer.

[0039] S2, add lead-zinc-based heat stabilizer and dioctyl ester to polyvinyl chloride raw material, the mass ratio of lead-zinc-based heat stabilizer masterbatch, dioctyl ester and polyvinyl chloride raw material is 2:0.08:100, extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain polyvinyl chloride plastic products. The performance test diagram of the mixed material during the rheological process is as follows Figure 2 shown.

[0040] Comparative Example 3 This comparative example provides a method for preparing a polyvinyl chloride plastic product, firstly using a lead-zinc-based heat stabilizer in a corresponding amount as in Example 3, and then preparing the polyvinyl chloride plastic product by using the lead-zinc-based heat stabilizer, specifically comprising the following steps: S1, weigh 410 parts of calcium stearate, 145 parts of zinc stearate, 925 parts of lead stearate, 965 parts of stearic acid, 1100 parts of tribasic lead sulfate, 1000 parts of calcium carbonate, 450 parts of paraffin, 200 parts of hydrotalcite, 200 parts of zeolite and 200 parts of polyol (a total of 5595 parts), melt-mix the raw materials at 110°C for 2h to obtain a lead-zinc based heat stabilizer.

[0041] S2, add lead-zinc-based heat stabilizer and triphenyl phosphite to polyvinyl chloride raw materials, the mass ratio of lead-zinc-based heat stabilizer masterbatch, triphenyl phosphite and polyvinyl chloride raw materials is 4:0.04:100, and extrude the obtained mixture through a rheometer at 190°C, cool to room temperature, and obtain polyvinyl chloride plastic products. The performance test diagram of the mixed material during the rheological process is as follows Figure 3 shown.

[0042] Comparative Example 4 This comparative example provides a method for preparing a polyvinyl chloride plastic product, firstly using a lead-zinc-based heat stabilizer in a corresponding amount as in Example 4, and then preparing the polyvinyl chloride plastic product by using the lead-zinc-based heat stabilizer, specifically comprising the following steps: S1, weigh 350 parts of calcium stearate, 125 parts of zinc stearate, 1175 parts of lead stearate, 650 parts of stearic acid, 1000 parts of tribasic lead sulfate, 1400 parts of calcium carbonate, 350 parts of PE wax, 100 parts of paraffin, 100 parts of antioxidant, 100 parts of hydrotalcite and 400 parts of zeolite (a total of 5750 parts), melt-mix the raw materials at 110°C for 2h to obtain a lead-zinc based heat stabilizer.

[0043] S2, add the lead-zinc-based heat stabilizer to the polyvinyl chloride raw material, the mass ratio of the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material is 3:100, and extrude the obtained mixture through a rheometer at 190°C, cool it to room temperature, and obtain a polyvinyl chloride plastic product. The performance test diagram of the mixed material during the rheological process is as follows Figure 4 shown.

[0044] Verification test The polyvinyl chloride plastic products provided in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to heat aging performance tests, with the heat aging temperature being 185°C ± 1°C. The test results are as follows: Figure 5 shown.

[0045] Depend on Figure 1~Figure 4 It can be seen that the plasticizing time of the rheological property change curve of the mixed material of the embodiment is shorter than that of the corresponding comparative example, the plasticity of the dynamic processing performance is better, and the physical properties of the processed products are also more excellent. Figure 5 It can be seen that, compared with the polyvinyl chloride plastic products of comparative examples 1 to 4, the polyvinyl chloride plastic products provided by embodiments 1 to 4 of the present invention have lighter colors, slower color changes, and better static stability.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for using a lead-zinc-based heat stabilizer masterbatch, characterized in that: The following steps are involved: Adding a lead-zinc-based heat stabilizer masterbatch into a polyvinyl chloride raw material, and molding the resulting mixture through a molding process to obtain a polyvinyl chloride plastic product; The components of the lead-zinc-based heat stabilizer masterbatch include zinc oxide, lead oxide, calcium hydroxide and stearic acid; the lead-zinc-based heat stabilizer masterbatch is prepared by physically mixing the components.

2. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 1, characterized in that: Calculated by weight, the components of the lead-zinc-based heat stabilizer masterbatch include: 15 to 25 parts of zinc oxide, 320 to 370 parts of lead oxide, 30 to 60 parts of calcium hydroxide and 1800 to 2100 parts of stearic acid.

3. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 1, characterized in that: The components of the lead-zinc-based heat stabilizer masterbatch also include at least two of tribasic lead sulfate, calcium carbonate, PE wax, paraffin or additives.

4. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 3, characterized in that: The auxiliary agent includes at least one of antioxidant, uracil, polyol, hydrotalcite, zeolite, magnesium oxide, bisphenol A, phosphite, calcium acetylacetonate, epoxy soybean oil or dipentaerythritol.

5. The method for using the lead-zinc-based heat stabilizer masterbatch according to any one of claims 2 to 4, characterized in that: Calculated by weight, the components of the lead-zinc-based heat stabilizer masterbatch include: 15 to 20 parts of zinc oxide, 330 to 370 parts of lead oxide, 35 to 55 parts of calcium hydroxide, 1900 to 2000 parts of stearic acid, 900 to 1100 parts of tribasic lead sulfate, 1300 to 1500 parts of calcium carbonate, 0 to 500 parts of PE wax, 0 to 500 parts of paraffin wax and 0 to 650 parts of additives.

6. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 1, characterized in that: The mass ratio of the lead-zinc-based heat stabilizer masterbatch to the polyvinyl chloride raw material is (2-4):

100.

7. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 1, characterized in that: The mixture also includes at least one of a plasticizer and a chelating agent.

8. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 7, characterized in that: The plasticizer includes at least one of dioctyl ester or dibutyl ester, and the chelating agent includes phosphite.

9. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 7, characterized in that: The masterbatch ratio of the plasticizer to the lead-zinc-based heat stabilizer is (0-5):100; The mass ratio of the chelating agent to the lead-zinc-based heat stabilizer masterbatch is (0-5):

100.

10. The method for using the lead-zinc-based heat stabilizer masterbatch according to claim 1, characterized in that: The molding process includes extrusion molding, calendering molding or injection molding; The molding temperature is 160°C to 230°C.

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