Compound stabilizer containing organic antimony
By using composite stabilizers of penta(isooctyl thioglycolate) antimony, calcium stearate and benzophenone in PVC, the problem of poor light stability of organic antimony stabilizers is solved, and the efficient thermal and photostability of PVC materials is achieved. reduces production costs.
Patent Information
- Application Number
- CN202411733544.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-02-11
AI Technical Summary
The existing organic antimony stabilizers have poor light stability under ultraviolet irradiation, resulting in color changes and mechanical properties of PVC materials during processing.
The photostability of the organic antimony stabilizer is improved through synergistic action.
It significantly improves the light stability and thermal stability of PVC, extends the service life of the material, and reduces production costs.
Abstract
Description
Technical Field
[0001] The invention relates to the field of stabilizers, and in particular to a composite stabilizer containing organic antimony. Background Art
[0002] Polyvinyl chloride (PVC) is a thermoplastic linear polymer produced by free radical polymerization of vinyl chloride monomers. It is one of the earliest plastics to be industrialized in the world. PVC is widely used in window frames, profiles, floor and wall coverings, pipes, cable insulation, garden hoses, inflatable pools and other products due to its mechanical, physical, electrical, low-cost, multifunctional and non-flammable advantages.
[0003] When PVC is heated, a dehydrochlorination reaction will occur. As the temperature rises, the thermal degradation rate accelerates, the degree of dehydrochlorination continues to deepen, and color changes and macromolecular cross-linking will occur. The direct consequence of degradation is not only a darkening of the color, but also a decrease in the mechanical properties of the material. The reason why PVC is easily degraded during processing is that there are unstable defects in the structure of the PVC molecular chain (such as allyl chloride structure and tertiary carbon chlorine structure, etc.).
[0004] In order to improve the poor thermal stability of PVC caused by thermal conditions and process it in all extrusion and molding temperature ranges, it is necessary to add a heat stabilizer. As one of the alternatives to the expensive organotin heat stabilizer, organic antimony stabilizers have been widely developed in recent years. Organic antimony stabilizers have the characteristics of high thermal stability efficiency, low toxicity, excellent initial coloring, and transparency. However, this type of stabilizer has poor light stability and will undergo a brown-black color change reaction when exposed to ultraviolet rays.
[0005] In summary, it is of great significance to develop a heat stabilizer with light stability and economic benefits for use in the field of PVC thermal stabilization. Summary of the invention
[0006] The present invention aims to solve the shortcomings of the above-mentioned prior art and provides an organic antimony composite heat stabilizer. The main stabilizer is antimony penta(isooctyl thioglycolate); the auxiliary stabilizer is calcium stearate and benzophenone. The technical solution of the present invention is as follows:
[0007] In the composite stabilizer of the present invention, each component is composed of the following components in parts by mass:
[0008] Antimony penta(2-ethylhexyl thioglycolate): 100 parts
[0009] Calcium stearate: 50 parts
[0010] Benzophenone: 50-100 parts.
[0011] Preferably, antimony penta(ethylhexyl thioglycolate) is a light yellow liquid with a slight odor of mercaptan and a refractive index of 1.4859.
[0012] Preferably, calcium stearate is a white powder with a molecular weight of 607.02 and a melting point of 150°C.
[0013] Preferably, benzophenone is white crystals with a melting point of 48.5°C and a boiling point of 305°C.
[0014] When the composite heat stabilizer of the present invention is applied to PVC, the formula is as follows:
[0015] Polyvinyl chloride: 100 parts
[0016] Dioctyl terephthalate (DOTP): 50 parts
[0017] Composite stabilizer: 0.5-3.0 parts
[0018] Specific implementation method of applying composite stabilizers to PVC processing:
[0019] The PVC processing process mainly includes three steps: mixing, refining, and pressing plate sample preparation. Weigh the PVC resin DOTP organic antimony composite stabilizer. First, use a high-speed mixer to mix the materials. The order of adding materials is PVC powder-DOTP-organic antimony composite stabilizer; add part of the composite heat stabilizer during the initial mixing and mix together for 15 minutes. When the material temperature reaches 60°C, add half of the DOTP and continue mixing for 15 minutes. The powder expands and the temperature reaches 90°C; then add the remaining half of the DOTP, and the material temperature reaches 100°C after mixing for 10 minutes; finally, add the remaining organic antimony composite stabilizer, mix for 10 minutes to reach 120°C and then discharge the material; then, the mixed PVC powder is refining, the refining temperature is controlled to be 180°C, the sheet thickness is 0.5mm, the refining time is 5 minutes, and the sheet is discharged after mixing evenly. Immediately after the sheet is discharged, it is hot-pressed using a flat vulcanizer. The hot pressing molding conditions were controlled as follows: preheating for 3 minutes, hot pressing for 1 minute, cold pressing for 5 minutes, the upper and lower templates were both at 160°C, and the size of the sample sheet after molding was 150×150×1mm. Finally, the PVC sheet was cut into squares with a side length of less than 2mm.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0021] 1. Organic antimony stabilizers have the characteristics of high thermal stability efficiency and low toxicity, but have the defect of poor light stability; calcium stearate is a common lubricant in PVC processing, and as a thermal stabilizer, it can have a good synergistic effect with organic antimony stabilizers; benzophenone is widely used as a UV absorber due to its good compatibility with most polymers and low cost. In addition, benzophenone can react with double bonds to help inhibit the initial coloring of PVC. The present invention utilizes the synergistic effect between organic antimony stabilizers, calcium stearate and benzophenone, which can not only improve the problem of poor light stability of organic antimony stabilizers, but also effectively improve the stability of PVC;
[0022] 2. From the cost point of view, the price of the above-mentioned antimony penta(ethyl thioglycolate) is much lower than that of methyl tin and butyl tin. At the same time, the cost of calcium stearate and benzophenone is relatively low. The composite stabilizer of the three has economic benefits.
[0023] PVC thermal stability test method:
[0024] The effect of the composite heat stabilizer of the present invention on the thermal stability of PVC is evaluated by using the Congo red test, with reference to the standard GB / T 2917.1-2002 "Congo red method for the determination of hydrogen chloride and any other acidic products released by blends and products based on vinyl chloride homopolymers and copolymers at high temperatures". A Congo red test paper is hung above the PVC sheet, heated to a constant temperature of 195°C, and the initial blueing time and complete blueing time of the Congo red test paper are observed and recorded. PVC will rapidly decompose and release hydrogen chloride gas at 170-180°C, and the Congo red test paper reacts with hydrogen chloride to turn blue. Adding a heat stabilizer inhibits its decomposition, and the quality of the composite heat stabilizer can be judged by the length of the initial and complete blueing time. DETAILED DESCRIPTION
[0025] [Example 1]
[0026] For the convenience of comparison, the experimental results are listed in Table 1.
[0027] Weigh 100 parts of PVC resin, 50 parts of DOTP, and organic antimony composite stabilizer [1.0 part of antimony penta(isooctyl thioglycolate), 0.5 parts of calcium stearate, and 1.0 part of benzophenone]. First, use a high-speed mixer to mix the materials. The order of adding materials is PVC powder-DOTP-organic antimony composite stabilizer; add part of the heat stabilizer during the initial mixing and mix together for 15 minutes. When the material temperature reaches 60°C, add half of the DOTP and continue mixing for 15 minutes. The powder expands and the temperature reaches 90°C; then add the remaining half of the DOTP, and after mixing for 10 minutes, the material temperature reaches 100°C; finally, add the remaining organic antimony composite stabilizer, mix for 10 minutes to reach 120°C, and then discharge the material; then, the mixed PVC powder is opened for refining, and the refining temperature is controlled to be 180°C, the sheet thickness is 0.5mm, the refining time is 5 minutes, and the sheet is discharged after mixing evenly. Immediately after the sheet is discharged, it is hot-pressed using a flat vulcanizer. The hot pressing molding conditions were controlled as follows: preheating for 3 minutes, hot pressing for 1 minute, and cold pressing for 5 minutes. The upper and lower templates were both at 160°C. The size of the sample sheet after molding was 150×150×1mm. Finally, the PVC sheet was cut into squares with a side length of less than 2mm for Congo red experiments.
[0028] [Example 2]
[0029] For the convenience of comparison, the experimental results are listed in Table 1.
[0030] Weigh 100 parts of PVC resin, 50 parts of DOTP, and organic antimony composite stabilizer [1.0 part of antimony penta(isooctyl thioglycolate), 0.5 parts of calcium stearate, and 0.5 parts of benzophenone]. First, use a high-speed mixer to mix the materials. The order of adding materials is PVC powder-DOTP-organic antimony composite stabilizer; add part of the heat stabilizer during the initial mixing and mix together for 15 minutes. When the material temperature reaches 60°C, add half of the DOTP and continue mixing for 15 minutes. The powder expands and the temperature reaches 90°C; then add the remaining half of the DOTP, and after mixing for 10 minutes, the material temperature reaches 100°C; finally, add the remaining organic antimony composite stabilizer, mix for 10 minutes to reach 120°C, and then discharge the material; then, the mixed PVC powder is opened for refining, and the refining temperature is controlled to be 180°C, the sheet thickness is 0.5mm, the refining time is 5 minutes, and the sheet is discharged after mixing evenly. Immediately after discharging, use a flat vulcanizer for hot pressing. The hot pressing molding conditions were controlled as follows: preheating for 3 minutes, hot pressing for 1 minute, and cold pressing for 5 minutes. The upper and lower templates were both at 160°C. The size of the sample sheet after molding was 150×150×1mm. Finally, the PVC sheet was cut into squares with a side length of less than 2mm for Congo red experiments.
[0031] [Example 3]
[0032] For the convenience of comparison, the experimental results are listed in Table 1.
[0033] Weigh 100 parts of PVC resin, 50 parts of DOTP, and organic antimony composite stabilizer [1.0 part of antimony penta(isooctyl thioglycolate)]. First, use a high-speed mixer to mix the materials. The order of adding materials is PVC powder-DOTP-organic antimony composite stabilizer; add part of the heat stabilizer during the initial mixing and mix together for 15 minutes. When the material temperature reaches 60°C, add half of the DOTP and continue mixing for 15 minutes. The powder expands and the temperature reaches 90°C; then add the remaining half of the DOTP, mix for 10 minutes, and the material temperature reaches 100°C; finally, add the remaining organic antimony composite stabilizer, mix for 10 minutes and reach 120°C before discharging the material; then, the mixed PVC powder is opened for refining, and the refining temperature is controlled to be 180°C, the sheet thickness is 0.5mm, the refining time is 5 minutes, and the sheet is discharged after mixing evenly. Immediately after discharging, use a flat vulcanizer for hot pressing. The hot pressing molding conditions were controlled as follows: preheating for 3 minutes, hot pressing for 1 minute, and cold pressing for 5 minutes. The upper and lower templates were both at 160°C. The size of the sample sheet after molding was 150×150×1mm. Finally, the PVC sheet was cut into squares with a side length of less than 2mm for Congo red experiments.
[0034] [Comparative Example 1]
[0035] For the convenience of comparison, the experimental results are listed in Table 1.
[0036] Weigh 100 parts of PVC resin and 50 parts of DOTP. First, use a high-speed mixer to mix the materials. The order of adding materials is PVC powder-DOTP; when the material temperature reaches 60°C, add half of DOTP and continue mixing for 15 minutes. The powder expands and the temperature reaches 90°C; add the remaining half of DOTP, mix for 10 minutes, and then discharge the material after the material temperature reaches 100°C; then, the mixed PVC powder is opened for refining, and the refining temperature is controlled to be 180°C, the sheet thickness is 0.5mm, the refining time is 5 minutes, and the sheet is discharged after mixing evenly. Immediately after the sheet is discharged, it is hot-pressed using a flat vulcanizer. The hot-pressing molding conditions are controlled at preheating for 3 minutes, hot pressing for 1 minute, and cold pressing for 5 minutes. The upper and lower templates are both 160°C. The size of the sample sheet after molding is 150×150×1mm. Finally, the PVC sheet is cut into squares with a side length of less than 2mm for Congo red experiments.
[0037] Table 1 Thermal stability test results of composite stabilizers with different ratios
[0038] Serial number Stabilizer Name Added amount (portion) Initial color change time / min Complete color change time / min Example 1 A / B / C 1.0 / 0.5 / 1.0 38 69 Example 2 A / B / C 1.0 / 0.5 / 0.5 32 53 Example 3 A 1.0 28 45 Comparative Example 1 none 0 5 7
[0039] Note: A-pentakis(2-ethylhexyl thioglycolate)antimony; B-calcium stearate; C-benzophenone
[0040] As can be seen from Table 1, compared with the sample of Comparative Example 1 without stabilizer, the initial discoloration time and complete discoloration time of the samples of Examples 1, 2, and 3 with stabilizer added are extended. Among them, the initial discoloration time and complete discoloration time of the ratio of 100 parts of PVC resin, 50 parts of DOTP, and organic antimony composite stabilizer [1.0 part of penta(isooctyl thioglycolate) antimony, 0.5 part of calcium stearate, and 1.0 part of benzophenone] adopted in Example 1 are the longest. This shows that the organic antimony composite stabilizer with a ratio of 1.0 part of penta(isooctyl thioglycolate) antimony, 0.5 part of calcium stearate, and 1.0 part of benzophenone has a good stabilizing effect.
[0041] The above content is a further detailed description of the present invention in combination with specific implementation methods, but the implementation methods of the present invention are not limited to the above embodiments, and any other changes, substitutions, modifications, combinations and simplifications that do not deviate from the spirit or principle of the present invention are within the protection scope of the present invention.
Claims
1. A composite stabilizer containing organic antimony, characterized in that: The components by mass are as follows: Antimony penta(2-ethylhexyl thioglycolate): 100 parts Calcium stearate: 50 parts Benzophenone: 50-100 parts.
2. The composite stabilizer containing organic antimony according to claim 1, characterized in that: The main stabilizer is antimony penta(ethylhexyl thioglycolate); the auxiliary stabilizers are calcium stearate and benzophenone.
3. The composite stabilizer containing organic antimony according to claim 1, characterized in that: The antimony penta(isooctyl thioglycolate) is a light yellow liquid with a slight odor of mercaptan and a refractive index of 1.4859.
4. The composite stabilizer containing organic antimony according to claim 1, characterized in that: The calcium stearate is white powder with a molecular weight of 607.02 and a melting point of 150°C.
5. The composite stabilizer containing organic antimony according to claim 1, characterized in that: The benzophenone is white crystals with a melting point of 48.5°C and a boiling point of 305°C.