A stabilizer for PVC, a PVC composite material and an article comprising the same

Abstract

This invention relates to a PVC stabilizer, PVC composite materials, and parts comprising the same, belonging to the technical field of polymer compound compositions. The PVC stabilizer of this invention includes cerium phosphomolybdate, which imparts good thermal stability and excellent long-term aging resistance to PVC composite materials.

Description

Technical Field

[0001] This invention relates to the field of polymer compound composition technology, and more particularly to a stabilizer for PVC, a PVC composite material, and an article containing the same. Background Technology

[0002] Polyvinyl chloride (PVC), the world's second most widely used plastic, suffers from a major drawback: its susceptibility to dehydrochlorination during thermal processing. This degrades the molecular chain structure, leading to yellowing and decreased physical properties. Heat stabilizers are typically added to inhibit this thermal degradation. Currently, mainstream heat stabilizers include lead salts, metal soaps, organotin compounds, and calcium / zinc (Ca / Zn) stabilizers. While lead salt stabilizers offer excellent thermal stability and are inexpensive, their toxicity has led to their gradual obsolescence. Organotin stabilizers offer good transparency and high efficiency, but are expensive and may produce an odor. Calcium / zinc stabilizers, on the other hand, suffer from poor initial whiteness and a tendency to "zinc burn" (i.e., sudden and rapid blackening). Furthermore, PVC experiences thermal aging during long-term use, resulting in deterioration of its mechanical properties. Therefore, there is an urgent need for a stabilizer that can effectively improve the thermal stability and long-term aging resistance of PVC. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a PVC stabilizer, a PVC composite material, and an article containing the same.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a stabilizer for PVC comprising cerium phosphomolybdate.

[0005] Ce in cerium phosphomolybdate 3+ With abundant 4f electrons, cerium phosphomolybdate can not only coordinate with HCl produced by PVC decomposition to effectively inhibit its catalytic degradation of PVC molecular chains, but also strongly coordinate with unstable chlorine atoms on PVC molecular chains to improve the stability of PVC molecular chains. At the same time, cerium phosphomolybdate also has a high thermal decomposition temperature, which can provide long-term and stable thermal protection during PVC processing or use, thereby endowing PVC composite materials with good thermal stability and excellent long-term aging resistance.

[0006] The preparation method of cerium phosphomolybdate may include the following steps: First, at least one of phosphomolybdic acid and its hydrate is mixed with water to obtain a clear and transparent mixture. Then, an aqueous solution of cerium chloride is slowly added to the mixture, and the mixture is reacted at 55°C to 65°C for 5 to 7 hours. After drying, cerium phosphomolybdate is obtained.

[0007] In some embodiments, the average particle size of cerium phosphomolybdate is 5 μm to 10 μm, for example, but not limited to 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm or 10 μm, or within the range of any two of the above values.

[0008] In a preferred embodiment of the PVC stabilizer described in this invention, the cerium phosphomolybdate has the chemical formula CePMo. 12 O 40 CePMo 12 O 40 The oxidation state of Ce in PVC is +3. Studies have found that when Ce is in other oxidation states (such as +4), it is difficult to effectively improve the thermal stability and long-term aging resistance of PVC composite materials.

[0009] As a preferred embodiment of the PVC stabilizer of the present invention, the mass fraction of cerium phosphomolybdate is 50% or more based on the total mass of the PVC stabilizer, for example, but not limited to 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%, or within the range of any two of the above values.

[0010] Secondly, the present invention provides a PVC composite material comprising PVC resin and a stabilizer, wherein the stabilizer is the aforementioned PVC stabilizer.

[0011] In a preferred embodiment of the PVC composite material of the present invention, the stabilizer has a mass fraction of 4% to 10% relative to the PVC resin, for example, but not limited to 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%, or falls within any two of the above values. A stabilizer mass fraction relative to the PVC resin within the above range is more conducive to the PVC composite material maintaining high thermal stability while also possessing good mechanical properties.

[0012] In a preferred embodiment of the PVC composite material of the present invention, the degree of polymerization of the PVC resin is 400 to 2500, for example, but not limited to 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400 or 2500, or within the range of any two of the above values.

[0013] In a preferred embodiment of the PVC composite material of the present invention, the PVC composite material further includes at least one of a plasticizer, a filler, and a lubricant.

[0014] In a preferred embodiment of the PVC composite material of the present invention, the plasticizer has a mass fraction of 20% to 100% relative to the PVC resin, for example, but not limited to 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%, or within the range of any two of the above values.

[0015] In a preferred embodiment of the PVC composite material of the present invention, the mass fraction of the lubricant relative to the PVC resin is 0.2% to 3%, for example, but not limited to 0.2%, 0.4%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8% or 3%, or within the range of any two of the above values.

[0016] In a preferred embodiment of the PVC composite material of the present invention, the filler has a mass fraction of less than 50% relative to the PVC resin, for example, but not limited to 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, or within the range of any two of the above values.

[0017] In a preferred embodiment of the PVC composite material of the present invention, the plasticizer includes at least one of dioctyl terephthalate, didecyl phthalate, dioctyl phthalate, dibutyl phthalate, diisooctyl phthalate, trioctyl trimellitate, trimellitate, n-octyl-n-decyl adipate, and dioctyl adipate-1,3-butanediol.

[0018] In a preferred embodiment of the PVC composite material of the present invention, the filler includes at least one of calcium carbonate, talc, and barium sulfate.

[0019] In a preferred embodiment of the PVC composite material of the present invention, the lubricant includes at least one of polyethylene wax, calcium stearate, and pentaerythritol ester.

[0020] The method for preparing the PVC composite material of the present invention includes the following steps: The components are mixed and plasticized to obtain a PVC composite material. For example, plasticization can be carried out using a mixer or an extruder (e.g., a single-screw extruder or a twin-screw extruder). For example, after the components are mixed evenly, they are mixed in a mixer at 165°C to 175°C for 10 to 20 minutes.

[0021] Thirdly, the present invention provides an article comprising the above-mentioned PVC stabilizer or the above-mentioned PVC composite material.

[0022] For example, the aforementioned components include, but are not limited to, electronic device housings, cable insulation sleeves, or sheaths.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: Ce in cerium phosphomolybdate 3+ With abundant 4f electrons, cerium phosphomolybdate can not only coordinate with HCl produced by PVC decomposition to effectively inhibit its catalytic degradation of PVC molecular chains, but also strongly coordinate with unstable chlorine atoms on PVC molecular chains to improve the stability of PVC molecular chains. At the same time, cerium phosphomolybdate also has a high thermal decomposition temperature, which can provide long-term and stable thermal protection during PVC processing or use, thereby endowing PVC composite materials with good thermal stability and excellent long-term aging resistance. Detailed Implementation

[0024] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0025] Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0026] 1. Raw materials and reagents 1) PVC resin PVC-1, degree of polymerization 1800, grade PVC-S80, manufacturer: Ningbo Formosa Plastics Chemical Co., Ltd. PVC-2, degree of polymerization 2500, grade S-PVC SH-200T, manufacturer: Shanghai Chlor-Alkali Chemical Co., Ltd.

[0027] 2) Plasticizers Plasticizer 1 is DOTP (dioctyl terephthalate), purchased from Zhuhai Liancheng Chemical Industry Co., Ltd.; Plasticizer 2 is DPHP (didecyl phthalate), purchased from Chaohu Xiangfeng Plastic Additives Co., Ltd.

[0028] 3) Lubricant Lubricant 1 is polyethylene wax, brand name 617A, manufactured by Honeywell International. Lubricant 2 is pentaerythritol ester, which is commercially available.

[0029] 4) Packing Calcium carbonate, particle size D50 approximately 4μm, commercially available.

[0030] 5) Stabilizer Stabilizer 1 is cerium phosphomolybdate (CePMo) 12 O 40 (This is a self-made product, prepared by the following method:) Weigh out phosphomolybdic acid hydrate (H3PMo) 12 O 40 CeCl3 powder (·28H2O) was placed in a three-necked flask, distilled water was added, and the mixture was magnetically stirred and continuously stirred in a 60°C water bath until the solution became clear and transparent. CeCl3 powder was weighed and dissolved in distilled water, and gradually added to the three-necked flask, resulting in the gradual formation of a precipitate. After maintaining magnetic stirring for 6 hours, the solution was concentrated and filtered. The resulting product was dried in a forced-air oven at 90°C for 48 hours to obtain CePMo. 12 O 40 The molar ratio of phosphomolybdic acid hydrate to CeCl3 is 1:1.

[0031] Stabilizer 2 is a calcium-zinc stabilizer, QY-307K5, manufactured by Guangdong Xinda New Material Technology Co., Ltd. Stabilizer 3 is H3PMo 12 O 40 A physical mixture of 28H2O (commercially available) and CeCl3 (commercially available), H3PMo 12 O 40 The molar ratio of 28H2O to CeCl3 is 1:1; Stabilizer 4 is a lanthanum trioctyl phosphate compound, prepared in-house using the following method: Mix 20 mL of 1.0 mol / L lanthanum trichloride aqueous solution with 0.02 mmol of trioctyl phosphate thoroughly and stir. Add 0.1 mol / L hydrochloric acid aqueous solution to adjust the pH to 5.0. Add the mixture to a separatory funnel, shake thoroughly, and allow it to stand to separate into layers. Collect the clear liquid in the upper layer, which is the lanthanum trioctyl phosphate compound.

[0032] Stabilizer 5 is cerium stearate, which is commercially available.

[0033] 2. Preparation method of the PVC composite material of the present invention According to the formula, PVC resin, plasticizer, lubricant, filler and stabilizer are mixed and then added to a mixer and mixed at 170±5℃ for 15 minutes to obtain flame retardant and smoke suppressant PVC composite material.

[0034] 3. Performance Testing 1) Color difference test: According to standard GB / T 3979-2008, using a D65 light source, the color difference of the sample before and after heat treatment (180℃, 4h) was measured on a Color-Eye 7000A colorimeter (X-Rite, USA), and expressed as ΔE.

[0035] 2) Tensile strength test: According to GB / T 1040.1-2018 standard, the tensile properties of the material before and after the heat aging test (conducted according to UL1581 standard, heat aging temperature is 121℃, time is 168h) were tested using a CMT4204 electronic universal testing machine (Shenzhen Xin Sansi Materials Testing Co., Ltd.), with a tensile rate of 50mm / min.

[0036] Table 1 shows the weight parts and properties of each component in the PVC composite materials of Examples 1 to 4. Table 2 shows the weight parts and properties of each component in the PVC composite materials of Examples 6 to 8. Table 3 shows the weight parts and properties of each component in the PVC composite materials of Examples 9 to 12. Table 4 shows the weight parts and properties of each component in the PVC composites of Comparative Examples 1 to 4. The " / " in Tables 1, 2, 3 and 4 indicates that there are no relevant parameters.

[0037] According to the data in Tables 1 to 3, the color difference (ΔE) of the PVC composite materials in Examples 1 to 10 before and after heat treatment at 180℃ for 4 hours is ≤13.3, and the tensile strength retention rate after heat aging at 121℃ for 168 hours is ≥95%, and the elongation at break retention rate is ≥90%. This indicates that cerium phosphomolybdate as the main component of the stabilizer can endow the PVC composite materials with good thermal stability and excellent long-term aging resistance.

[0038] According to Example 1 and Comparative Example 1, when cerium phosphomolybdate is used as the main component of the stabilizer, it has no significant effect on the initial tensile strength and elongation at break of the material, but its effect on improving the thermal stability of PVC is significantly better than that of conventional commercial heat stabilizers (such as calcium-zinc stabilizers), and it can also significantly improve the long-term aging resistance of PVC; according to Comparative Examples 2 to 4, it can also be found that when H3PMo 12 O 40Physical mixtures of 28H2O and CeCl3, or lanthanum trioctyl phosphate compounds and cerium stearate as stabilizers, not only have limited effect on improving the thermal stability of PVC, but also have difficulty in effectively improving the long-term aging resistance of PVC.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A stabilizer for PVC, characterized in that, Including cerium phosphomolybdate.

2. The PVC stabilizer as described in claim 1, characterized in that, The chemical formula of the cerium phosphomolybdate is CePMo. 12 O 40 .

3. The PVC stabilizer as described in claim 1, characterized in that, Based on the total mass of the stabilizer for PVC, the mass fraction of cerium phosphomolybdate is 50% or more.

4. A PVC composite material, characterized in that, It includes PVC resin and a stabilizer, wherein the stabilizer is the PVC stabilizer according to any one of claims 1 to 3.

5. The PVC composite material as described in claim 4, characterized in that, The stabilizer has a mass fraction of 4% to 10% relative to the PVC resin.

6. The PVC composite material as described in claim 4, characterized in that, The degree of polymerization of the PVC resin is between 400 and 2500.

7. The PVC composite material as described in claim 4, characterized in that, The PVC composite material also includes at least one of plasticizer, filler, and lubricant.

8. The PVC composite material as described in claim 7, characterized in that, At least one of the following conditions must be met: (1) The plasticizer has a mass fraction of 20% to 100% relative to the PVC resin; (2) The lubricant has a mass fraction of 0.2% to 3% relative to the PVC resin; (3) The filler has a mass fraction of less than 50% relative to the PVC resin.

9. The PVC composite material as described in claim 7, characterized in that, At least one of the following conditions must be met: (1) The plasticizer includes at least one of dioctyl terephthalate, didecyl phthalate, dioctyl phthalate, dibutyl phthalate, diisooctyl phthalate, trioctyl trimellitate, trimellitate, n-octyl-n-decyl adipic acid, and dioctyl adipic acid-1,3-butanediol. (2) The filler includes at least one of calcium carbonate, talc, and barium sulfate; (3) The lubricant includes at least one of polyethylene wax, calcium stearate, and pentaerythritol ester.

10. A component, characterized in that, It includes the PVC stabilizer according to any one of claims 1 to 3 or the PVC composite material according to any one of claims 4 to 9.

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