Powder stabilizer for transparent hard plastic and transparent hard PVC (polyvinyl chloride)

Abstract

The invention belongs to the technical field of transparent hard plastics, and particularly relates to a powder stabilizer for transparent hard plastics and hard PVC (polyvinyl chloride). The powder stabilizer is prepared from zinc / calcium lysine matched with other auxiliary materials. Wherein the content of the lysine salt is 20%-30%. The powder stabilizer can significantly improve the thermal stability and transparency of a hard PVC product, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of transparent rigid plastics, and particularly relates to a powder stabilizer for transparent rigid plastics and a transparent rigid PVC. BACKGROUND

[0002] Polyvinyl chloride (PVC) is a general-purpose plastic widely used in various fields. Due to its formulation adjustability, it can achieve diversified product forms from high transparency to opacity, rigidity to softness by adding different additives. Regardless of the formulation system, stabilizers need to be added during the molding process to suppress the degradation of PVC. According to the composition of the stabilizer, it can be divided into organic tin, lead salt, barium zinc, cadmium barium zinc, calcium zinc, etc.

[0003] Among them, transparent rigid PVC is widely used in medical, packaging, building materials and other fields due to its excellent optical properties, high strength and chemical resistance. The stabilizer used in the current transparent rigid PVC product is still organic tin, of which the most important one is octyl tin. However, there are certain problems in the use of organic tin stabilizers. In addition to the extremely high price, it will release mercaptan odor when the processing temperature exceeds 190℃, and it is easy to stick to the roller, affecting the processing.

[0004] CN2022108296785 (a kind of transparent environmental protection zinc-based stabilizer and its preparation method) discloses a kind of based on zinc benzoate+stearic acid zinc stabilizer, the product application scene is mainly soft PVC product, it is known from the test formula of DINP 20 phr of it.But when the application object is rigid PVC product, the plasticizer content is 0 phr. Epoxy fatty acid calcium / zinc stabilizer has been proved to improve the thermal stability of the product, but the improvement of transparency is not ideal. CN2023112382203 (a method for one-step synthesis of natural amino acid zinc salt environmental protection PVC heat stabilizer and its application) discloses a kind of based on tryptophan zinc stabilizer, but only the thermal stability of the product is improved.

[0005] Medical, packaging and other fields also have high requirements for environmental protection, so there is an urgent need for an environmentally friendly stabilizer suitable for transparent rigid PVC products. SUMMARY

[0006] In view of the above problems, a kind of transparent rigid plastic powder stabilizer and its preparation method, a kind of transparent rigid plastic powder stabilizer and a kind of transparent rigid PVC are provided to improve the stability and transparency of the product. The technical scheme of the present application is as follows:

[0007] Firstly, the present application provides a kind of powder stabilizer for transparent rigid plastics, the powder stabilizer contains lysine metal salt, the lysine metal salt is calcium lysine or zinc lysine or a mixture of calcium lysine and zinc lysine, and the mass percentage content of the lysine metal salt in the powder stabilizer is 20% to 30%.

[0008] Preferably, the powder stabilizer further contains an antioxidant with a mass percentage content of 3% to 10%. Further preferably, the antioxidant is at least one selected from the group consisting of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0009] Preferably, the powder stabilizer further contains hydrotalcite with a mass percentage content of 40% to 50%. Further preferably, the hydrotalcite is at least one selected from the group consisting of zinc-magnesium-aluminum hydrotalcite and magnesium-aluminum hydrotalcite.

[0010] Preferably, the powder stabilizer further contains a benzene ring-containing auxiliary stabilizer with a mass percentage content of 7% to 20%. Further preferably, the benzene ring-containing auxiliary stabilizer is at least one selected from the group consisting of stearylbenzoyl methane, 1-phenyldecan-1,3-dione, and dibenzoylmethane. Stearylbenzoyl methane, 1-phenyldecan-1,3-dione, and dibenzoylmethane all have a diketone structure and are generally also referred to as diketone auxiliary stabilizers.

[0011] Preferably, the powder stabilizer further contains an epoxy group-containing auxiliary stabilizer with a mass percentage content of 5% to 15%. Further preferably, the epoxy group-containing auxiliary stabilizer is at least one selected from the group consisting of epoxidized soybean oil and octyl epoxy stearate.

[0012] Preferably, the powder stabilizer further contains a secondary auxiliary stabilizer, and the secondary auxiliary stabilizer is a phosphite.

[0013] Secondly, the present application provides a transparent hard PVC product containing the aforementioned powder stabilizer, and the transparent hard PVC product is made of the following raw materials: PVC resin powder, the aforementioned powder stabilizer, MBS, P501, P770, G70S, and G16. In the transparent hard PVC product, the addition amount of the aforementioned powder stabilizer is 1.5 phr to 3 phr.

[0014] wherein MBS, P501, P770, G70S, and G16 are all commercially available PVC processing aids. For example, MBS is a methyl methacrylate processing aid; LOXIOL G70S and LOXIOL G16 are commonly used lubricants; P501 and P770 belong to commonly used ACR processing aids.

[0015] The present application has the following beneficial effects:

[0016] The powder stabilizer of the present application does not cause burning when used in transparent rigid PVC products, and calcium / zinc lysine is healthy in itself, and the powder stabilizer can unexpectedly significantly improve the heat stabilizer and transparency of the product when used in transparent rigid PVC products. DETAILED DESCRIPTION

[0017] The technical ideas, schemes, effects, etc. of the present application are described in detail below through specific examples. The examples are only exemplary descriptions of the present application and are not considered to limit the scope of protection of the present application. The preparation methods of zinc lysine, zinc benzoate / stearate stabilizer (transparent environmentally friendly zinc-based stabilizer), zinc tryptophan, and calcium zinc epoxy fatty acid stabilizer used in the following examples / counter examples are referred to the following references, wherein zinc lysine / calcium can also be prepared by the method of the examples:

[0018] Zinc lysine: CN119822983A (CN2025100929321 Preparation and use of monomeric zinc lysine and its conversion into zinc lysine complex)

[0019] Zinc benzoate and zinc stearate stabilizer (transparent environmentally friendly zinc-based stabilizer): CN115353666A (CN202210829678.5 A transparent environmentally friendly zinc-based stabilizer and a preparation method thereof).

[0020] Zinc tryptophan: CN117362749A (CN2023112382203 A method for one-step synthesis of natural amino acid zinc salt environmentally friendly PVC heat stabilizer and its application).

[0021] Calcium zinc epoxy fatty acid: Guo Lixin, Wan Qinghong, Cui Yanyan. Direct synthesis of calcium / zinc epoxy fatty acid and its effect on PVC heat stabilization [J]. Rubber technology and equipment, 2006, 32(012): 6-9.

[0022] In the following examples / counter examples, Phr is the abbreviation of Parts per hundred parts of resin, which represents the amount of additives to be mixed per 100 parts of resin.

[0023] PVC resin powder used in the examples / counter examples is SG-7 from Xinjiang Tianye Co., Ltd. Other raw materials are commercially available. For example, MBS can be selected from Japan Zhong Yuan B-521; P501 can be selected from Japan Mitsubishi product, and P770 can be selected from France Arkema.

[0024] Example 1 Preparation of a powder stabilizer for transparent rigid plastic and PVC product

[0025] (1) Lysine zinc preparation: 0.1 mol of lysine hydrochloride was weighed and dissolved in 200 ml of water, and the pH was adjusted to 7.6 using NaOH. Under stirring at 80°C, 50 ml of 1 mol / L ZnCl2 solution was slowly added dropwise. The addition was completed in 1 h, and the pH was maintained at 7.5-7.8 for 2 h of reaction. The solution was concentrated under reduced pressure to 30-50 ml, 200 ml of anhydrous ethanol was added, the precipitate was filtered, and the precipitate was vacuum dried at 35°C to obtain lysine zinc. The structure confirmation information of lysine zinc is as follows: 1 H NMR (CDCI3, 400 MHz) δ: 8.54 (s, 4H, -NH2), 3.38 (t, J = 7.2 Hz, 2H, -CH), 2.88 (s, 4H, -NH2), 2.78 (t, J = 7.6 Hz, 4H, -CH2), 1.64-1.10 (m, 12H, -CH2).

[0026] (2) Powder stabilizer preparation: The following formula raw materials were mixed and compounded at room temperature (room temperature) to prepare a powder stabilizer (the amount of each ingredient was calculated based on the mass percentage): 20% lysine zinc, 5% tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, 50% zinc-magnesium-aluminum hydrotalcite, 20% stearylbenzoylmethane, and 5% epoxy soybean oil.

[0027] (3) PVC sample preparation: 100 phr of PVC resin powder, 2 phr of the powder stabilizer prepared in step (2), 6 phr of MBS, 1 phr of P5011, 1 phr of P7701, 0.5 phr of G70S, and 0.5 phr of G16 were mixed uniformly. The mixture was plasticized on a 200°C double roller mill at a speed of 10*8 rpm (i.e., the front roller speed was 10 rpm and the rear roller speed was 8 rpm) for 5 min. The plasticized sample was pressed into a 50 mm*20 mm*1 mm sample sheet on a flat vulcanizing machine at 160°C according to the mold.

[0028] Example 2 Preparation of a powder stabilizer for transparent hard plastic and a PVC product

[0029] (1) Lysine calcium preparation: 0.1 mol of lysine hydrochloride was weighed and dissolved in 200 ml of water, and the pH was adjusted to 7.8 using NaOH. Under stirring at 80°C, 50 ml of 1 mol / L CaCl2 solution was slowly added dropwise. The addition was completed in 1.5 h, and the pH was maintained at 7.5-7.8 for 2 h of reaction. The solution was concentrated under reduced pressure to 30-50 ml, 200 ml of anhydrous ethanol was added, the precipitate was filtered, and the precipitate was vacuum dried at 35°C to obtain lysine calcium. The structure confirmation information of lysine calcium is as follows: 1H NMR (CDC13, 400 MHz) δ: 8.56 (s, 4H, -NH2), 3.42 (t, J = 7.6 Hz, 2H, -CH), 2.98 (s, 4H, -NH2), 2.76 (t, J = 7.2 Hz, 4H, -CH2), 1.68-1.12 (m, 12H, -CH2).

[0030] (2) Powder stabilizer preparation: the following formula raw materials were used for mixing and compounding at room temperature (room temperature) to prepare the powder stabilizer (the compounding amount was calculated according to the mass percentage): 25% calcium lysine, 10% β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-octadecyl, 40% magnesium-aluminum hydrotalcite, 15% 1-phenyl decane-1,3-dione, 10% octyl epoxy stearate.

[0031] (3) PVC sample preparation: 100 phr of PVC resin powder, 2 phr of the powder stabilizer prepared in step (2), 6 phr of MBS, 1 phr of P5011, 1 phr of P7701, 0.5 phr of G70S, and 0.5 phr of G16 were uniformly mixed; the mixture was plasticized on a 200°C double roller open mill at a speed of 10*8 rpm for 5 min; and the plasticized sample was pressed into a 50mm*20mm*1mm sample sheet on a flat plate vulcanizing machine at 160°C according to the mold.

[0032] Example 3 Preparation of a powder stabilizer for transparent hard plastic and a PVC product

[0033] (1) Preparation of zinc lysine: 0.1 mol of lysine hydrochloride was dissolved in 200 ml of water, and NaOH was used to adjust the pH to 7.5; 50 ml of 1 mol / L ZnCl2 solution was slowly added dropwise under stirring at 80°C, and the dropwise addition was completed in 1.2 h; the pH was maintained at 7.5-7.8, and the reaction was performed for 2 h; the solution was concentrated to 30-50 ml under reduced pressure; 200 ml of anhydrous ethanol was added; the precipitate was filtered; and the precipitate was vacuum dried at 35°C to obtain zinc lysine. The NMR data of zinc lysine were the same as in Example 1.

[0034] (2) Preparation of calcium lysine: 0.1 mol of lysine hydrochloride was dissolved in 200 ml of water, and NaOH was used to adjust the pH to 7.8; 50 ml of 1 mol / L CaCl2 solution was slowly added dropwise under stirring at 80°C, and the dropwise addition was completed in 1.3 h; the pH was maintained at 7.5-7.8, and the reaction was performed for 2 h; the solution was concentrated to 30-50 ml under reduced pressure; 200 ml of anhydrous ethanol was added; the precipitate was filtered; and the precipitate was vacuum dried at 35°C to obtain calcium lysine. The NMR data of calcium lysine were the same as in Example 2.

[0035] (3) Powder stabilizer preparation: the following formula raw materials are used for mixing and compounding (the amount of compounding is calculated according to mass percentage) at room temperature (room temperature) to prepare a powder stabilizer: 15% zinc lysine, 15% calcium lysine, 3% 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 5% phosphite, 20% zinc-magnesium-aluminum hydrotalcite, 20% magnesium-aluminum hydrotalcite, 7% stearylbenzoyl methane, 15% epoxy soybean oil.

[0036] (4) PVC sample preparation: 100 phr of PVC resin powder, 2 phr of the powder stabilizer prepared in step (3), 6 phr of MBS, 1 phr of P5011, 1 phr of P7701, 0.5 phr of G70S, and 0.5 phr of G16 are uniformly mixed; the sample after plasticization is pressed into a 50 mm*20 mm*1 mm sample sheet at 160°C according to the mold on a flat vulcanizing machine.

[0037] Example 4 Performance comparison test of different calcium-zinc stabilizers

[0038] The following comparative sample and test results in the development process are provided:

[0039] Comparative sample 1:

[0040] PVC sample preparation: 100 phr of PVC resin powder, 2 phr of commercially available powder composite calcium-zinc stabilizer (zinc calcium stearate stabilizer), 6 phr of MBS, 1 phr of P5011, 1 phr of P7701, 0.5 phr of G70S, and 0.5 phr of G16 are uniformly mixed; the sample after plasticization is pressed into a 50 mm*20 mm*1 mm sample sheet at 160°C according to the mold on a flat vulcanizing machine.

[0041] Comparative sample 2:

[0042] PVC sample preparation: 100 phr of PVC resin powder, 2 phr of the stabilizer according to the formula in Example 1 of patent document CN 115353666A, 6 phr of MBS, 1 phr of P5011, 1 phr of P7701, 0.5 phr of G70S, and 0.5 phr of G16 are uniformly mixed; the sample after plasticization is pressed into a 50 mm*20 mm*1 mm sample sheet at 160°C according to the mold on a flat vulcanizing machine.

[0043] Comparative sample 3:

[0044] PVC sample preparation: PVC resin powder 100 phr, zinc tryptophan 2 phr, MBS 6 phr, P5011 phr, P7701 phr, G70S 0.5 phr, G16 0.5 phr were uniformly mixed; plasticized at 200°C double roller open mill 10*8 rpm speed for 5 min; the sample after plasticizing was pressed into 50mm*20mm*1mm sample sheet according to the mold at 160°C on a flat vulcanizing machine.

[0045] Comparative example 4 sample:

[0046] PVC sample preparation: PVC resin powder 100 phr, zinc tryptophan 2 phr, MBS 6 phr, P5011 phr, P7701 phr, G70S 0.5 phr, G16 0.5 phr were uniformly mixed; plasticized at 200°C double roller open mill 10*8 rpm speed for 5 min; the sample after plasticizing was pressed into 50mm*20mm*1mm sample sheet according to the mold at 160°C on a flat vulcanizing machine.

[0047] Note: In the sample preparation stage, only examples and comparative examples 1 and 4 can be normally completed, and comparative examples 2 and 3 all occur different degrees of burning material in the sample preparation process.

[0048] The PVC samples of the examples and comparative examples were tested for Congo red stabilization time, 190°C oven static stabilization time, and GB / T 2410-2008 light transmittance. The test results are shown in Table 1.

[0049] Table 1 Performance test results of PVC samples

[0050]

[0051] Because the samples of comparative examples 2 and 3 burned (the essence of burning is poor thermal stability, and the sample preparation method in this case is double roller open mill sample preparation, and burning indicates poor dynamic thermal stability), testing cannot be performed and the use requirements are not met. Therefore, Table 1 shows the sample determination results of examples 1-3 and comparative examples 1 and 4.

[0052] Overall, all the example samples are significantly better than the comparative examples in Congo red stabilization time, oven static stabilization time, and light transmittance. The powder stabilizer of the application has good performance in long-term thermal stability and transparency.

[0053] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can make equivalent substitutions or changes to the technical solutions and inventive concepts of the application within the technical scope disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A transparent powder stabilizer for rigid plastics, characterized in that, The powder stabilizer contains a lysine metal salt, the lysine metal salt is calcium lysinate or zinc lysinate or a mixture of calcium lysinate and zinc lysinate, and the mass percentage content of the lysine metal salt in the powder stabilizer is 20-30%.

2. The powder stabilizer for a transparent hard plastic according to claim 1, characterized by The powder stabilizer further contains an antioxidant with a mass percentage content of 3-10%.

3. The powder stabilizer for a transparent hard plastic according to claim 2, characterized by The antioxidant is at least one selected from the group consisting of tetra[β- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, β- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, and 2, 2'-methylenebis (4-methyl-6-tert-butylphenol).

4. The powder stabilizer for a transparent hard plastic according to claim 1, wherein The powder stabilizer further contains hydrotalcite with a mass percentage content of 40-50%.

5. The powder stabilizer for a transparent hard plastic according to claim 1, wherein The powder stabilizer further contains a benzene ring-containing auxiliary stabilizer with a mass percentage content of 7-20%.

6. The powder stabilizer for a transparent hard plastic according to claim 5, wherein The benzene ring-containing auxiliary stabilizer is at least one selected from the group consisting of stearylbenzoyl methane, 1-phenyldecane-1, 3-dione, and dibenzoylmethane.

7. The powder stabilizer for a transparent hard plastic according to claim 1, wherein The powder stabilizer further contains an epoxy group-containing auxiliary stabilizer with a mass percentage content of 5-15%.

8. The powder stabilizer for a transparent hard plastic according to claim 8, characterized by The epoxy group-containing auxiliary stabilizer is at least one selected from the group consisting of epoxidized soybean oil and octyl epoxystearate.

9. The powder stabilizer for a transparent hard plastic according to claim 1, wherein The powder stabilizer further contains a phosphite.

10. A transparent rigid PVC article prepared using the powder stabilizer for transparent rigid plastics according to any one of claims 1 to 9, characterized in that, In the transparent rigid PVC product, the addition amount of the powder stabilizer is 1.5-3 phr; the transparent rigid PVC product further contains MBS, P501, P770, G70S, and G16.

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