Rare earth compound stabilizer for PVC (polyvinyl chloride) and preparation method of rare earth compound stabilizer

Abstract

The invention provides a rare earth compound stabilizer for PVC (polyvinyl chloride) and a preparation method of the rare earth compound stabilizer. The rare earth compound stabilizer comprises the following components in parts by weight: 2-10 parts of triazine carboxylic acid rare earth salt, 1-5 parts of stearate and 1-5 parts of a functional additive, and the preparation method comprises the following steps: putting the triazine carboxylic acid rare earth salt, the stearate and the functional additive into a ball milling tank according to the parts by weight, adding absolute ethyl alcohol, mixing for 10-20 minutes at 200-500rpm, and performing post-treatment to obtain the rare earth compound stabilizer. The rare earth compound stabilizer effectively improves the mechanical property, the thermal stability and the light aging resistance of the PVC material, and the rare earth compound stabilizer is rich in raw material source, simple in preparation process and suitable for industrial large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of PVC stabilizers, and in particular relates to a rare earth composite stabilizer for PVC and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is one of the most widely used synthetic resins in the world. It has the advantages of light texture, good chemical corrosion resistance, excellent mechanical properties, and simple production process. However, the defect of PVC is that its decomposition temperature is usually lower than the processing temperature. When it is above 100°C or exposed to sunlight for a long time, it will decompose to produce hydrogen chloride, and further autocatalytic decomposition will cause discoloration and rapid decline in physical and mechanical properties. Therefore, in order to prevent the decomposition of PVC resin during processing and molding, stabilizers must be added.

[0003] At present, the widely used PVC stabilizers can be mainly divided into lead salt stabilizers, metal soap stabilizers, organic tin stabilizers, calcium zinc stabilizers and rare earth stabilizers. Among them, rare earth stabilizers are a new type of stabilizer developed in recent years, which have the advantages of low toxicity, good transparency and high weather resistance. However, when used alone, there are still problems such as poor initial thermal stability of the material. In the prior art, rare earth salts are modified by using carboxylic acid compounds such as imidazole-4,5-dicarboxylic acid. Although the thermal stability of the stabilizer obtained is improved, the light stability is relatively poor, and the thermal stability still needs to be further improved.

[0004] In order to improve the stability of rare earth stabilizers, the prior art improves the thermal stability of rare earth stabilizers by adding functional additives such as polyurea. However, although the thermal stability is improved when applied to PVC materials, there are still disadvantages such as low mechanical properties and poor initial thermal stability of the material, and the light stability is still relatively poor, resulting in the material being improved. The effect is not obvious.

[0005] In view of the problems existing in the prior art, how to provide a rare earth composite stabilizer so that the prepared PVC material has better mechanical properties, thermal stability and light aging resistance is a problem to be solved urgently in the present invention. Summary of the invention

[0006] The object of the present invention is to provide a rare earth composite stabilizer for PVC and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides a rare earth composite stabilizer for PVC, characterized in that the rare earth composite stabilizer comprises the following components in parts by weight: 2-10 parts of triazine carboxylic acid rare earth salt, 1-5 parts of stearate, and 1-5 parts of functional additives;

[0008] The triazine carboxylic acid rare earth salt is 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt;

[0009] The functional auxiliary agent is modified polyurea.

[0010] As a further improvement, the synthesis of the 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt comprises the following steps:

[0011] (1) stirring and dissolving a rare earth salt in deionized water, adding 2,4,6-tris(aminocaproyl)-1,3,5-triazine and anhydrous ethanol thereto, and heating and refluxing at 60-70° C. for reaction while stirring;

[0012] (2) After adding NaOH solution to step (1) to adjust the pH value to 6-7, stirring is continued for 2-3 hours, and post-treatment is performed to obtain 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine rare earth salt.

[0013] As a further improvement, the rare earth salt is at least one of rare earth chloride, rare earth nitrate or rare earth sulfate.

[0014] As a further improvement, the rare earth is at least one of the light rare earth elements of lanthanum, cerium, praseodymium, neodymium, promethium, samarium and europium.

[0015] As a further improvement, the modified polyurea is prepared by reacting isocyanate, polyetheramine and silane coupling agent.

[0016] As a further improvement, the synthesis of the modified polyurea comprises the following steps:

[0017] (1) slowly adding an isocyanate dissolved in an organic solvent to the polyetheramine while stirring, and reacting for 1-3 hours under a nitrogen atmosphere;

[0018] (2) Add a silane coupling agent to step (1), continue stirring the reaction for 1-3 hours, and after the reaction is completed, perform post-treatment to obtain a modified polyurea.

[0019] As a further improvement, the isocyanate is at least one of hexamethylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0020] In order to have better mechanical properties, preferably, the isocyanate is 4,4'-diphenylmethane diisocyanate.

[0021] As a further improvement, the silane coupling agent is at least one of KH-550, KH-570, KH-540, and A-151.

[0022] In order to have better stability, preferably, the silane coupling agent is KH-550 and the organic solvent is N,N-dimethylformamide.

[0023] As a further improvement, the stearate is at least one of calcium stearate, zinc stearate, barium stearate, aluminum stearate, magnesium stearate, and sodium stearate.

[0024] In order to have better stability, preferably, the stearate is calcium stearate.

[0025] The present invention provides a method for preparing a rare earth composite stabilizer for PVC, characterized in that it comprises the following steps:

[0026] The triazine carboxylic acid rare earth salt, stearate and functional additive are placed in a ball mill, anhydrous ethanol is added, and the mixture is mixed at 200-500 rpm for 10-20 minutes, and then post-processed to obtain a rare earth composite stabilizer.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The invention provides a rare earth composite stabilizer for PVC and a preparation method thereof. When the prepared rare earth composite stabilizer is used in PVC material, not only the mechanical properties of the PVC material are improved, but also the thermal stability and light aging resistance of the PVC material can be significantly improved. The raw material source of the rare earth composite stabilizer is abundant, the preparation process is simple, and the rare earth composite stabilizer is suitable for industrial large-scale production. DETAILED DESCRIPTION

[0029] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0030] In the following examples, except for triazine carboxylic acid rare earth salt, imidazole carboxylic acid rare earth salt, polyurea, and modified polyurea, the remaining compound monomers and related reagents used can be purchased from the market, among which 2,4,6-tris(aminocaproic acid)-1,3,5-triazine was purchased from Jiangsu Aikon Biopharmaceutical Research and Development Co., Ltd., model AK00IDFP, polyetheramine was purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd., model P108071, and PVC was purchased from Guangdong Weilinna New Materials Technology Co., Ltd., model PVC1302.

[0031] The preparation method of 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt comprises the following steps:

[0032] (1) 10 mmol of lanthanum nitrate hexahydrate was dissolved in 20 mL of deionized water by stirring, and then 10 mmol of 2,4,6-tris(aminocaproyl)-1,3,5-triazine and 20 mL of anhydrous ethanol were added thereto, and the mixture was heated under reflux at 60° C. and stirred for half an hour;

[0033] (2) After adding 1 mol / L NaOH solution to step (1) to adjust the pH value to 6, stirring was continued for 2 h. After the reaction was completed, suction filtration was performed, and the mixture was repeatedly washed with anhydrous ethanol and water for 3 times. The obtained solid was dried at 80° C. to obtain 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine rare earth salt.

[0034] The preparation method of imidazole-4,5-dicarboxylic acid rare earth salt comprises the following steps:

[0035] (1) 8 mmol of imidazole-4,5-dicarboxylic acid was dissolved in 20 mL of deionized water by stirring, and then 5 mmol of lanthanum chloride solution was added thereto, and the mixture was heated under reflux at 60° C. and stirred for half an hour;

[0036] (2) After adding 1 mol / L NaOH solution to step (1) to adjust the pH value to 5, stirring was continued for 5 hours. After the reaction was completed, suction filtration was performed and the mixture was repeatedly washed with deionized water for 3 times. The obtained solid was dried at 80° C. to obtain imidazole-4,5-dicarboxylic acid rare earth salt.

[0037] The preparation method of polyurea comprises the following steps:

[0038] 11mmol 4,4'-diphenylmethane diisocyanate was dissolved in 30mL N,N-dimethylformamide liquid, then slowly added dropwise to 10mmol polyetheramine while stirring, and reacted for 3h under nitrogen atmosphere. After the reaction was completed, the mixture was dried at 110°C for 50min to obtain polyurea.

[0039] The preparation method of modified polyurea comprises the following steps:

[0040] (1) 11 mmol of 4,4'-diphenylmethane diisocyanate was dissolved in 30 mL of N,N-dimethylformamide, and then slowly added dropwise to 10 mmol of polyetheramine while stirring, and stirred for reaction for 2 h under nitrogen atmosphere;

[0041] (2) Add 1 mmol of silane coupling agent KH-550 to step (1), stir and react for 3 h, and after the reaction is completed, bake at 110° C. for 30 min to obtain modified polyurea.

[0042] The preparation method of Examples 1-3 and Comparative Example 2 comprises the following steps:

[0043] According to weight proportions, triazine carboxylic acid rare earth salt, stearate and functional additives were put into a ball mill, 30 mL of anhydrous ethanol was added for mixing, the mixture was mixed at 300 rpm for 20 min, filtered and dried with cold air to obtain a rare earth composite stabilizer.

[0044] The preparation method of Comparative Example 1 comprises the following steps:

[0045] According to weight proportions, imidazole carboxylic acid rare earth salt, stearate and functional additives were put into a ball mill, 30 mL of anhydrous ethanol was added to mix, the mixture was mixed at 300 rpm for 20 min, filtered and dried with cold air to obtain a rare earth composite stabilizer.

[0046] The components and contents used in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1 below:

[0047] Table 1

[0048]

[0049] Take 100 parts of PVC and 5 parts of composite stabilizer by weight, stir mechanically at 40°C for 30 minutes at a stirring speed of 800 rpm to obtain PVC formula material, and perform performance tests accordingly.

[0050] The test method is as follows:

[0051] Tensile strength: tested according to GB / T 1040-2006;

[0052] Impact strength: tested according to GB / T 1043-1993;

[0053] Bending strength: tested according to GB / T 9341-2008;

[0054] Congo red discoloration: tested according to GB / T 2917.1-2002;

[0055] Light aging resistance: The test was conducted according to GB / T 16422.3-2014. The wavelength of the UV lamp was 313nm. The samples were exposed to light at 70°C for a total of 300 hours. The tensile strength test was conducted every 150 hours.

[0056] The test results are shown in Table 2 and Table 3, as follows:

[0057] Table 2

[0058]

[0059] Table 3

[0060]

[0061] It can be seen from Example 2 and Comparative Example 1 in Tables 2 and 3 that, compared with the rare earth composite stabilizer prepared from imidazole-4,5-dicarboxylic acid rare earth salt, the rare earth composite stabilizer prepared from 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt, when applied to PVC material, has a smaller change in tensile strength with the increase of light aging time, indicating that the light aging resistance is better, the Congo red turns blue for a longer time, the thermal stability is good, and the impact strength and flexural strength of the PVC material can be improved to a certain extent.

[0062] It can be seen from Example 2 and Comparative Example 2 that, compared with the rare earth composite stabilizer prepared by using conventional functional additives such as unmodified polyurea, the rare earth composite stabilizer prepared by using silane coupling agent to modify polyurea has better tensile strength, impact strength and flexural strength when applied to PVC materials, and can also prolong the time for Congo red to turn blue to a certain extent, indicating that the thermal stability is better. At the same time, with the increase of light aging time, the change in tensile strength is small, and the anti-light aging performance is better.

[0063] It can be seen from the test results of Examples 1-3 that when the rare earth composite stabilizer prepared by the preparation method provided by the present invention is applied to PVC material, it has better tensile strength, impact strength, and flexural strength, indicating that the mechanical properties are better, and has a longer Congo red to blue time, indicating that the heat resistance is better, and even under a longer illumination time, the PVC material still has good tensile strength, indicating that the anti-light aging performance is better.

[0064] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A rare earth composite stabilizer for PVC, characterized in that: The rare earth composite stabilizer comprises the following components in parts by weight: 2-10 parts of triazine carboxylic acid rare earth salt, 1-5 parts of stearate, and 1-5 parts of functional additive; The triazine carboxylic acid rare earth salt is 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt; The functional auxiliary agent is modified polyurea.

2. A rare earth composite stabilizer for PVC according to claim 1, characterized in that: The preparation method of the 2,4,6-tris(aminocaproic acid)-1,3,5-triazine rare earth salt comprises the following steps: (1) stirring and dissolving a rare earth salt in deionized water, adding 2,4,6-tris(aminocaproyl)-1,3,5-triazine and anhydrous ethanol thereto, and heating and refluxing at 60-70° C. for reaction while stirring; (2) After adding NaOH solution to step (1) to adjust the pH value to 6-7, stirring is continued for 2-3 hours, and post-treatment is performed to obtain 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine rare earth salt.

3. A rare earth composite stabilizer for PVC according to claim 1 or 2, characterized in that: The rare earth salt is at least one of rare earth chloride, rare earth nitrate or rare earth sulfate.

4. A rare earth composite stabilizer for PVC according to claim 3, characterized in that: The rare earth is at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium and europium.

5. A rare earth composite stabilizer for PVC according to claim 1, characterized in that: The modified polyurea is prepared by reacting isocyanate, polyether amine and silane coupling agent.

6. A rare earth composite stabilizer for PVC according to claim 1, characterized in that: The synthesis of the modified polyurea comprises the following steps: (1) slowly adding an isocyanate dissolved in an organic solvent to the polyetheramine while stirring, and reacting for 1-3 hours under a nitrogen atmosphere; (2) Add a silane coupling agent to step (1), continue stirring the reaction for 1-3 hours, and after the reaction is completed, perform post-treatment to obtain a modified polyurea.

7. A rare earth composite stabilizer for PVC according to claim 5 or 6, characterized in that: The isocyanate is at least one of hexamethylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate, and 4,4'-diphenylmethane diisocyanate.

8. A rare earth composite stabilizer for PVC according to claim 5 or 6, characterized in that: The silane coupling agent is at least one of KH-550, KH-570, KH-540 and A-151.

9. A rare earth composite stabilizer for PVC according to claim 1, characterized in that: The stearate is at least one of calcium stearate, zinc stearate, barium stearate, aluminum stearate, magnesium stearate, and sodium stearate.

10. The method for preparing a rare earth composite stabilizer for PVC according to claim 1, characterized in that: The following steps are involved: The triazine carboxylic acid rare earth salt, stearate and functional additive are placed in a ball mill, anhydrous ethanol is added, and the mixture is mixed at 200-500 rpm for 10-20 minutes, and then post-processed to obtain a rare earth composite stabilizer.

Images