Environment-friendly heat stabilizer for PVC (polyvinyl chloride) processing and use method of environment-friendly heat stabilizer

Abstract

The invention discloses an environment-friendly heat stabilizer for PVC (polyvinyl chloride) processing and a use method thereof, and belongs to the technical field of environment-friendly heat stabilizers for PVC processing. The environment-friendly heat stabilizer for PVC processing is prepared from the following components in parts by weight: 25 to 40 parts of epoxy compound, 12 to 20 parts of sodium mercaptide, 2 to 5 parts of carboxylic acid compound, 5 to 10 parts of glycidyl methacrylate (GMA) and 8 to 10 parts of monomer pentaerythritol triacrylate (PETA). The environment-friendly heat stabilizer for PVC processing is not easy to seep from a PVC product, the PVC processing process is more environment-friendly and is not easy to degrade, and the heat sensitivity of PVC is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of PVC heat stabilizers, and in particular to an environmentally friendly heat stabilizer for PVC processing and a use method thereof. Background Art

[0002] Unstable structures on the PVC molecular chain, such as chlorine atoms (tertiary chlorine) and allyl chlorine on tertiary carbon atoms, are active centers for thermal degradation. Under the action of heat, these unstable chlorine atoms are easily detached, forming free radicals and producing double bonds. In this process, unstable chlorine atoms become chlorine free radicals (Cl·) and detach from the PVC chain, while producing HCl gas. The newly formed double bonds and adjacent chlorine atoms can further promote the degradation reaction, forming more double bonds and free radicals, leading to further breakage of the PVC molecular chain.

[0003] During the thermal degradation process, the presence of oxygen and light accelerates this reaction because they can react with the newly formed double bonds to form peroxide radicals, which further attack the PVC molecular chain, resulting in more chain breakage and HCl release. And during the polymerization of PVC, due to the presence of oxygen, oxygen-containing carbonyl allyl groups can appear on the growing PVC macromolecule chain in the polymerization reaction, which is a catalyst for the dehydrochlorination of PVC macromolecules. In addition, the presence of HCl will also catalyze the degradation of PVC because it can attack other chlorine atoms in the PVC molecular chain, prompting them to detach and form more free radicals and double bonds. Therefore, in order to prevent the thermal degradation of PVC during processing and use at 160-180°C, thermal stabilizers need to be added. These stabilizers can capture free radicals to prevent chain breakage, or react with HCl to reduce its attack on the PVC molecular chain, thereby improving the thermal stability of PVC. Metal soaps, such as calcium stearate and zinc stearate, mainly work by reacting with the released HCl to form stable metal chlorides. Although they are cost-effective and provide good thermal stability, they may have limited effects in high temperature or humid environments. Epoxy stabilizers react with HCl released during the degradation of PVC to form stable chlorides and promote cross-linking between PVC molecular chains, thereby improving the thermal stability of PVC. They are particularly effective in high temperature and humid environments. They have the advantages of light stability and non-toxicity, and are suitable for soft PVC products, especially those that need to be exposed to sunlight. However, a major disadvantage of epoxy compounds is that they easily seep out of PVC products, which will affect the long-term performance and appearance of PVC products. This seepage phenomenon is particularly obvious in rigid PVC products. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide an environmentally friendly heat stabilizer for PVC processing, which is not easy to seep out from PVC products, is more environmentally friendly during PVC processing, is not easy to degrade, and reduces the thermal sensitivity of PVC.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] An environmentally friendly heat stabilizer for PVC processing comprises, by weight, 25-40 parts of epoxy compounds, 12-20 parts of sodium thiolate, 2-5 parts of carboxylic acid compounds, 5-10 parts of glycidyl methacrylate (GMA), and 8-10 parts of pentaerythritol triacrylate (PETA).

[0007] Furthermore, the epoxy compound is selected from one of epoxy soybean oil and epoxy linseed oil.

[0008] Furthermore, the sodium thiolate is one of sodium methylthiolate, sodium ethylthiolate, 4-methylbenzenethiol sodium salt, sodium mercaptobenzothiazole, 1H-1,2,3-triazole-4-thiol sodium salt, and 1H-1,2,3-triazole-4-thiol sodium salt.

[0009] Furthermore, the sodium thiolate is a multifunctional sodium thiolate, and the multifunctional sodium thiolate is one of G-2S(A), PE-2S, PE-3S, PE-4S, and TMP-3S.

[0010] Furthermore, the sodium thiolate is a multifunctional sodium thiolate, and the multifunctional sodium thiolate is one of G-2S(A), PE-2S, PE-3S, PE-4S, and TMP-3S.

[0011] The invention also comprises 5-10 parts of antioxidants supported by the nano-carrier.

[0012] The present invention also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0013] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0014] S2. Add the environmentally friendly heat stabilizer for PVC processing into PVC resin, stir evenly, and then during the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing during the processing at 160-180° C., cool and shape, and obtain PVC products.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention provides a method for using an environmentally friendly heat stabilizer for PVC processing. The sulfur atom on the sodium thiolate carries a lone pair of electrons. As a nucleophilic reagent, it first forms a thioester group with a carboxylic acid compound, and can attack the C-Cl bond of PVC during the heating process, replace the C-Cl bond, and simultaneously censor sodium chloride. Compared with the prior art, it does not remove hydrogen chloride to form a carbon-carbon double bond, thereby avoiding the effect of hydrogen chloride on the accelerated decomposition of PVC. Epoxy compounds are low-VOC compounds. As an environmentally friendly heat stabilizer for conventional PVC processing, glycidyl methacrylate (GMA) is added at the same time, which helps to improve the compatibility of epoxy compounds and PVC and prevent them from easily seeping out of PVC products; the monomer pentaerythritol triacrylate (PETA) is also added, which acts as a crosslinking agent introduced through a grafting reaction, such as pentaerythritol triacrylate (PETA), which can increase the crosslinking degree of PVC and improve its heat resistance, and may react with carbonyl allyl groups, thereby reducing their number and reducing the thermal sensitivity of PVC.

[0017] (2) The present invention provides a method for using an environmentally friendly heat stabilizer for PVC processing, wherein the sodium thiolate is a multifunctional sodium thiolate, and the multifunctional sodium thiolate is one of G-2S(A), PE-2S, PE-3S, PE-4S, and TMP-3S. The multifunctional sodium thiolate has multiple thiol groups, and the multiple thiol groups can react with epoxy compounds and epoxy groups of glycidyl methacrylate (GMA), thereby further improving the compatibility of epoxy compounds and PVC. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0019] Figure 1 It is a graph showing the results of the dynamic thermal stability test of Example 1 and the comparative example in the experimental example;

[0020] Figure 2 It is a graph showing the static thermal stability test results of Example 1 and the comparative example in the experimental example. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0022] Epoxides: Epoxides such as epoxidized soybean oil can improve the thermal stability of PVC. Epoxides react with hydrogen chloride to generate chloroethanol, which, under the catalysis of metal soaps, replaces unstable chlorine atoms in PVC to play a stabilizing role.

[0023] Example 1

[0024] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 25 parts of epoxy soybean oil, 15 parts of sodium methyl mercaptan, 2 parts of carboxylic acid compound acetic acid, 5 parts of glycidyl methacrylate (GMA), and 10 parts of pentaerythritol triacrylate (PETA).

[0025] Furthermore, the sodium thiolate is one of sodium methylthiolate, sodium ethylthiolate, 4-methylbenzenethiol sodium salt, sodium mercaptobenzothiazole, 1H-1,2,3-triazole-4-thiol sodium salt, and 1H-1,2,3-triazole-4-thiol sodium salt.

[0026] Furthermore, the sodium thiolate is a multifunctional sodium thiolate, and the multifunctional sodium thiolate is one of G-2S(A), PE-2S, PE-3S, PE-4S, and TMP-3S.

[0027] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0028] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0029] S2. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0030] G-2S(A): 1,3-Dimercapto-2-propanol, CAS No.584-04-3, is a colorless transparent liquid with a refractive index of 1.566.

[0031] PE-2S: 2,2-Bis(mercaptomethyl)-1,3-propanediol, CAS No.19333-66-5, white solid, melting point 95°C.

[0032] PE-3S: 3-mercapto-2,2-bis(mercaptomethyl)-1-propanol, CAS No.500283-12-5, is a colorless to slightly yellow solid with a melting point of 35°C.

[0033] PE-4S: 2,2-Bis(mercaptomethyl)-1,3-propanedithiol, CAS No.4720-60-9, a colorless to slightly yellow solid with a melting point of 71°C.

[0034] TMP-3S: 2-Ethyl-2-(mercaptomethyl)-1,3-propanedithiol, CAS No.

[0035] 121318-18-1 is a colorless to slightly yellow solid with a melting point of 45°C.

[0036] Sodium thiomethoxide (Sodium methanethiolate): chemical formula is CH3NaS, CAS number is 5188-07-8.

[0037] Sodium ethanethiolate (Sodium ethanethiolate; Sodium ethyl mercaptide): The chemical formula is C2H6NaS, and the CAS number is 811-51-8.

[0038] 4-Methylbenzenethiol sodium salt (Benzenethiol, 4-methyl-, sodium salt): chemical formula is C7H7NaS, CAS number is 10486-08-5.

[0039] Sodium mercaptobenzothiazole: The chemical formula is C7H4NNaS2, and the CAS number is 2492-26-4.

[0040] 1H-1,2,3-Triazole-4-thiol sodium salt (1,2,3-Thiadiazole-5-thiol): chemical formula is C2H2N2S2, CAS number is 69893-92-1.

[0041] 2-Propanethiol, 2-methyl-, sodium salt: chemical formula is C4H9NaS, CAS number is 29364-29-2.

[0042] Example 2

[0043] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 40 parts of epoxy linseed oil, 20 parts of 4-methylbenzenethiol sodium salt, 3 parts of carboxylic acid compound acetic acid, 8 parts of glycidyl methacrylate (GMA), and 9 parts of pentaerythritol triacrylate (PETA).

[0044] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0045] S2. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0046] S1. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0047] Example 3

[0048] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 35 parts of epoxy soybean oil, 12 parts of 2-methyl-2-propanethiol sodium salt, 5 parts of carboxylic acid compound acetic acid, 10 parts of glycidyl methacrylate (GMA), and 8 parts of pentaerythritol triacrylate (PETA).

[0049] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0050] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0051] S2. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0052] Example 4

[0053] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 25 parts of epoxy soybean oil, 15 parts of multifunctional sodium thiolate PE-2S, 2 parts of carboxylic acid compound acetic acid, 5 parts of glycidyl methacrylate (GMA), 10 parts of pentaerythritol triacrylate (PETA), and 10 parts of an antioxidant supported by a silica nanocarrier.

[0054] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0055] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0056] S2. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0057] Example 5

[0058] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 25 parts of epoxy soybean oil, 15 parts of multifunctional sodium thiolate TMP-3S, 2 parts of carboxylic acid compound acetic acid, 5 parts of glycidyl methacrylate (GMA), 10 parts of pentaerythritol triacrylate (PETA), and 5 parts of an antioxidant supported by a silica nanocarrier.

[0059] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0060] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0061] S2. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0062] Example 6

[0063] The present embodiment provides an environmentally friendly heat stabilizer for PVC processing, which includes, by weight, 25 parts of epoxy soybean oil, 15 parts of multifunctional sodium thiolate PE-2S, 2 parts of carboxylic acid compound acetic acid, 5 parts of glycidyl methacrylate (GMA), 10 parts of pentaerythritol triacrylate (PETA), and 8 parts of an antioxidant supported by a silica nanocarrier.

[0064] This embodiment also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0065] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0066] S2. Add the environmentally friendly heat stabilizer for PVC processing to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, in the extrusion or calendering process of PVC, the environmentally friendly heat stabilizer for PVC processing prevents the PVC from decomposing due to high temperature during the processing of 160-180°C, and cools and shapes to obtain PVC products.

[0067] Comparative Example

[0068] Different from Example 1, the environmentally friendly heat stabilizer for PVC processing provided in this comparative example includes 25 parts of epoxy soybean oil, 5 parts of glycidyl methacrylate (GMA), and 10 parts of pentaerythritol triacrylate (PETA) in terms of weight.

[0069] This comparative example also provides a method for using an environmentally friendly heat stabilizer for PVC processing, comprising the following steps:

[0070] S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing;

[0071] S2. Add the environmentally friendly heat stabilizer for PVC processing of this comparative example to the PVC resin, stir evenly in a double-roll open mill, and mix. After mixing, cool and shape during the extrusion or calendering process of the PVC to obtain a PVC product.

[0072] Test example

[0073] The film in step S2 of the method for using an environmentally friendly heat stabilizer for PVC processing in Example 1 and the comparative example is added to the PVC resin, mixed and dispersed evenly in a double-roll open mill, and kneaded. The kneading conditions are: heating to 165°C in the two stages of kneading, the speed of the rollers in the double-roll open mill is 20 revolutions per minute, providing the necessary shear force, and then preparing it into a PVC film sample, using GB 2409-1980 dynamic heat stability test standard to carry out dynamic heat stability experiment, using GB / T 9349-2002 polyvinyl chloride, related chlorine-containing homopolymers and copolymers and their blends Determination of thermal stability color change method to carry out static heat stability experiment, the dynamic heat stability experiment is to continue three heating stages, the conditions are that the three heating stages are heated to 190°C, the speed of the rollers in the double-roll open mill is 60 revolutions per minute, providing the necessary shear force, so as to mix and plasticize PVC in the actual processing process, and then prepare it into a PVC film sample, the initial whiteness test results are as follows Figure 1The static thermal stability test is carried out in the laboratory by placing the PVC film sample in a thermal aging oven at a temperature of 196°C, a 275W bulb, and a blast. The initial whiteness test results are shown in Figure 2 As shown. Figure 1 and Figure 2 It can be seen that in the dynamic thermal stability experiment and the static thermal stability experiment, as the heating time increases, the PVC film sample prepared in Example 1 is whiter than the PVC film sample prepared in the comparative example, and the yellowing process is slower, indicating that the PVC product prepared in Example 1 is more stable during high-temperature thermal aging.

[0074] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An environmentally friendly heat stabilizer for PVC processing, characterized in that: Calculated by weight, the composition comprises 25-40 parts of epoxy compound, 12-20 parts of sodium thiolate, 2-5 parts of carboxylic acid compound, 5-10 parts of glycidyl methacrylate (GMA), and 8-10 parts of pentaerythritol triacrylate (PETA).

2. An environmentally friendly heat stabilizer for PVC processing as claimed in claim 1, characterized in that: The epoxy compound is selected from one of epoxy soybean oil and epoxy linseed oil.

3. An environmentally friendly heat stabilizer for PVC processing as claimed in claim 2, characterized in that: The sodium thiolate is one of sodium methylthiolate, sodium ethylthiolate, 4-methylbenzenethiol sodium salt, sodium mercaptobenzothiazole, 1H-1,2,3-triazole-4-thiol sodium salt, and 1H-1,2,3-triazole-4-thiol sodium salt.

4. An environmentally friendly heat stabilizer for PVC processing as claimed in claim 1, characterized in that: The sodium thiolate is a multifunctional sodium thiolate, and the multifunctional sodium thiolate is one of G-2S(A), PE-2S, PE-3S, PE-4S, and TMP-3S.

5. An environmentally friendly heat stabilizer for PVC processing as claimed in claim 1, characterized in that: The carboxylic acid compound is acetic acid.

6. An environmentally friendly heat stabilizer for PVC processing as claimed in claim 1, characterized in that: The invention also comprises 5-10 parts of antioxidants supported by the nano-carrier.

7. The method for using the environmentally friendly heat stabilizer for PVC processing according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh the components of the environmentally friendly heat stabilizer for PVC processing according to the formula amount, mix them evenly in a high-speed mixer, and prepare the environmentally friendly heat stabilizer for PVC processing; S2, adding the environmentally friendly heat stabilizer for PVC processing to PVC resin, stirring evenly, and then in the process of extrusion or calendering of PVC, the environmentally friendly heat stabilizer for PVC processing prevents PVC from decomposing during the processing at 160-180° C., cooling and shaping, and obtaining PVC products.

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