A PVC plasticizer and preparation method thereof

Abstract

The present invention provides a PVC plasticizer and a preparation method thereof, relating to the technical field of PVC processing aids. The PVC plasticizer contains a benzene ring, an ester group, a fatty chain, an epoxy group, a hydroxyl group and a thiol group. The thiol group is introduced to form a chemical bond between the plasticizer and a PVC main resin. Through the synergistic effect of the benzene ring, the ester group, the fatty chain, the epoxy group, the hydroxyl group and the thiol group, the PVC plasticizer has an excellent plasticizing effect and low migration, and also has a high-efficiency thermal stabilization effect, which helps to improve the mechanical properties of the product. Therefore, the PVC plasticizer can be widely used in various PVC soft products.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC processing aids, in particular to a PVC plasticizer and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is one of the world's five most common plastics and is widely used in a variety of fields, including the chemical industry, construction, light industry, packaging, and cables. However, due to the high polarity between PVC molecules, a large amount of plasticizer must be added when used in soft products.

[0003] Plasticizers are functional additives added to polymers to improve their flexibility, plasticity, processability, and stretchability, and are widely used in PVC products. Commonly used plasticizers, depending on their chemical structure, primarily include carboxylates, hydrocarbons, phosphates, polyethylene glycols, and epoxides. Traditional phthalate plasticizers (such as DOTP) account for a significant portion of these plasticizers. However, with growing environmental awareness, and particularly the discovery of potential health risks and environmental pollution from phthalate plasticizers, their use has become increasingly limited. The development of green plasticizers that can replace phthalates has become a hot topic.

[0004] Cardanol is a natural phenolic compound containing unsaturated long-chain hydrocarbons, derived from cashew nut shells, a low-value agricultural and forestry residue. It is a commonly used natural resource with unique advantages such as being renewable, inexpensive, and widely available. Furthermore, cardanol combines the reactivity of phenolic compounds with the flexibility of aliphatic compounds. Its unique chemical structure allows it to react with a wide range of organic and inorganic compounds to modify their structures. Existing research indicates that cardanol and its derivatives have been used as plasticizers in the polymer and rubber industries, demonstrating excellent plasticizing properties.

[0005] However, both DOTP plasticizers and existing plant-based plasticizers such as cardanol have high migration properties. The migration of DOTP plasticizers will lead to deterioration of product performance and harm the environment or human health. Although plant-based plasticizers have the advantages of being environmentally friendly and non-toxic, they will also cause product degradation after migration, which will ultimately affect the service life of the product.

[0006] In view of this, developing a plasticizer with low migration is a technical problem that needs to be solved urgently. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: in order to solve the problem of high plasticizer migration in the prior art, the present invention provides a PVC plasticizer, which introduces a thiol group to chemically bond the plasticizer to the PVC main resin, thereby reducing the migration and solving the problem of high plasticizer migration in the prior art.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] A PVC plasticizer, the structural formula of which is shown below:

[0010]

[0011] Another object of the present invention is to provide a method for preparing the PVC plasticizer as described above, comprising the steps of:

[0012] S1: Add cardanol, oleic acid, catalyst A, and methylhydroquinone to xylene, heat to 150-180°C, stir for 2-3 hours, let stand, cool to room temperature, and vacuum concentrate the solution; add sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate, filter, and dry the filtrate in vacuum at 60°C to obtain intermediate product I;

[0013] S2: The intermediate product I, glacial acetic acid, and toluene were added to a three-necked flask, stirred magnetically, and heated to 60-65°C. Hydrogen peroxide was added dropwise and reacted for 3-6 hours. The mixture was cooled to room temperature and washed with deionized water until neutral. The organic phase was separated and distilled under reduced pressure and dried under vacuum at 60°C for 4 hours to obtain the intermediate product II.

[0014] S3: Place the intermediate product II, mercaptopropionic acid, and catalyst B in a three-necked flask, stir at 100-130°C, cool to room temperature, add dichloromethane for extraction, wash three times with sodium bicarbonate aqueous solution, and then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 60°C for 4 hours to obtain a PVC plasticizer.

[0015] Optionally, the catalyst A is selected from at least one of p-toluenesulfonic acid, tetrabutyl titanate, and hypophosphorous acid.

[0016] Optionally, the catalyst B is selected from at least one of triphenylphosphine, tetrabutylammonium bromide, and N,N-dimethylbenzylamine.

[0017] Optionally, the mass concentration of the sodium bicarbonate aqueous solution in step S1 is 2 wt %; the usage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is 1 mol: (1-1.2) mol: 200 mL: 500 mL: 500 mL.

[0018] Optionally, the amount of the catalyst A used is 1% of the total mass of the reactants in step S1; the amount of the methylhydroquinone used is 0.5% of the total mass of the reactants in step S1.

[0019] Optionally, in step S2, the usage ratio of the intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is 1 mol:4 mol:400 mL:(2-4) mol.

[0020] Optionally, the mass concentration of the sodium bicarbonate aqueous solution in step S3 is 2 wt %; the usage ratio of the intermediate product II, dichloromethane, the sodium bicarbonate aqueous solution, and deionized water is 1 mol:400 mL:500 mL:500 mL.

[0021] Optionally, the usage ratio of the intermediate product II in step S3 and mercaptopropionic acid is (1.5-4) mol:1 mol based on the epoxy group:carboxyl group.

[0022] Optionally, the amount of catalyst B used is 1.5% of the total mass of the reactants in step S3.

[0023] The beneficial effects of the present invention are:

[0024] The PVC plasticizer provided by the present invention has an excellent plasticizing effect and low migration, and also has a high-efficiency thermal stabilization effect through the synergistic effect of benzene rings, ester groups, fatty chains, epoxy groups, hydroxyl groups, and mercapto groups, which helps to improve the mechanical properties of products. Therefore, the PVC plasticizer can be widely used in various PVC soft products. DETAILED DESCRIPTION

[0025] The present invention will now be described in further detail. The embodiments described below are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0026] In order to solve the problem of high plasticizer migration in the prior art, the present invention provides a PVC plasticizer, the structural formula of the PVC plasticizer is shown as follows:

[0027]

[0028] The PVC plasticizer provided by the present invention contains a benzene ring, an ester group, an aliphatic chain, an epoxy group, a hydroxyl group and a thiol group, wherein the benzene ring and the ester group are directly connected, and the structure thereof is similar to that of phthalate, and has excellent plasticizing properties. In addition, the epoxy group has weak polarity and can relieve the strong polar force between PVC molecular chains, thereby having a plasticizing effect. The multiple long aliphatic chains can provide plasticizing effects and reduce the processing temperature of PVC. The ester group and the epoxy group can both adsorb HCl generated by the decomposition of PVC, so that the PVC plasticizer has an excellent auxiliary stability effect. The polyhydroxy structure has a good auxiliary thermal stability effect. In addition, by introducing a thiol group, the thiol group in the PVC plasticizer can undergo a thiol-ene click reaction with the double bond formed during the degradation of PVC. On the one hand, the PVC plasticizer is chemically linked to the PVC, thereby avoiding migration and precipitation of the PVC plasticizer during processing and use, achieving safety and environmental protection, and improving the mechanical strength of the PVC. On the other hand, the PVC can be prevented from discoloration and degradation, and has excellent thermal stability.

[0029] The PVC plasticizer provided by the present invention has an excellent plasticizing effect and low migration, and also has a high-efficiency thermal stabilization effect through the synergistic effect of benzene rings, ester groups, fatty chains, epoxy groups, hydroxyl groups, and mercapto groups, which helps to improve the mechanical properties of products. Therefore, the PVC plasticizer can be widely used in various PVC soft products.

[0030] Another object of the present invention is to provide a method for preparing the PVC plasticizer as described above, the preparation method comprising the following steps:

[0031] S1: Add cardanol, oleic acid, catalyst A, and methylhydroquinone to xylene, heat to 150-180°C, stir for 2-3 hours, let stand, cool to room temperature, and vacuum concentrate the solution to enrich the residual components; slowly add sodium bicarbonate aqueous solution to wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate, filter, and dry the filtrate in vacuum at 60°C to obtain intermediate product I;

[0032] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 60-65°C, add hydrogen peroxide dropwise, react for 3-6 hours, cool to room temperature, wash with deionized water until neutral, separate the liquids, take the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 hours to obtain intermediate product II;

[0033] S3: Place the intermediate product II, mercaptopropionic acid, and catalyst B in a three-necked flask, stir at 100-130°C for 1-3 hours, then cool to room temperature, add dichloromethane for extraction, wash three times with sodium bicarbonate aqueous solution, and then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer.

[0034] The preparation process of the PVC plasticizer provided by the present invention is as follows:

[0035]

[0036] The present invention uses cardanol, oleic acid, glacial acetic acid, hydrogen peroxide, mercaptopropionic acid and the like as raw materials, and obtains a novel PVC plasticizer material simultaneously containing a benzene ring, an ester group, a fatty chain, an epoxy group, a hydroxyl group and a thiol structure through multi-step reactions such as esterification, oxidation and ring opening. The novel PVC plasticizer has an excellent plasticizing effect and does not migrate, while also having a highly efficient thermal stabilization effect due to the synergistic effect of the benzene ring, ester group, fatty chain, epoxy group, hydroxyl group and thiol structure. Furthermore, the raw materials are widely available, and the cardanol and oleic acid are plant-based and green and renewable. This material not only effectively solves the problem of currently commonly used small molecule plasticizers deteriorating product performance and being harmful to the environment due to migration, but also helps to improve the mechanical properties of the products. The material can be widely used in various PVC soft products.

[0037] In the present invention, the catalyst A is preferably selected from at least one of p-toluenesulfonic acid, tetrabutyl titanate, and hypophosphorous acid; and the catalyst B is selected from at least one of triphenylphosphine, tetrabutylammonium bromide, and N,N-dimethylbenzylamine.

[0038] In order to ensure the smooth progress of the reaction while taking into account the performance of the PVC plasticizer, the mass concentration of the sodium bicarbonate aqueous solution in step S1 of the present invention is preferably 2wt%; the amount ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is 1 mol: (1-1.2) mol: 200 mL: 500 mL: 500 mL; preferably

[0039] The amount of catalyst A used in step S1 is 1% of the total mass of the reactants; the amount of methylhydroquinone used in step S1 is 0.5% of the total mass of the reactants; the amount ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide in step S2 is 1 mol:4 mol:400 mL:(2-4) mol; the mass concentration of the sodium bicarbonate aqueous solution in step S3 is 2 wt%; the amount ratio of intermediate product II, dichloromethane, sodium bicarbonate aqueous solution, and deionized water is 1 mol:400 mL:500 mL:500 mL; the amount ratio of intermediate product II and mercaptopropionic acid in step S3 is (1.5-4) mol:1 mol based on the epoxy group:carboxyl group; and the amount of catalyst B used in step S3 is 1.5% of the total mass of the reactants.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0041] Example 1

[0042] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0043] S1: Add cardanol, oleic acid, p-toluenesulfonic acid, and methylhydroquinone to xylene, heat to 170°C and vigorously stir for 3 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution to wash three times, wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0044] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.1 mol: 200 mL: 500 mL: 500 mL;

[0045] The amount of p-toluenesulfonic acid used is 1% of the total mass of the reactants;

[0046] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0047] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0048] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 60°C, and begin dropwise addition of hydrogen peroxide. React for 6 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, and remove the organic phase, evaporate under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0049] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0050] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0051] S3: Place the intermediate product II, mercaptopropionic acid, and triphenylphosphine in a three-necked flask, stir at 110°C for 2 hours, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it over anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0052] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0053] The ratio of the intermediate product II and mercaptopropionic acid is 2.5 mol:1 mol based on the epoxy group:carboxyl group;

[0054] The amount of triphenylphosphine used was 1.5% of the total mass of the reactants.

[0055] Its infrared data is as follows: 3383cm -1 :-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0056] Example 2

[0057] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0058] S1: Add cardanol, oleic acid, tetrabutyl titanate, and methylhydroquinone to xylene, heat to 150°C and vigorously stir for 3 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution to wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0059] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1 mol: 200 mL: 500 mL: 500 mL;

[0060] The amount of tetrabutyl titanate used is 1% of the total mass of the reactants;

[0061] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0062] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0063] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 65°C, and begin dropwise addition of hydrogen peroxide. React for 3 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, and remove the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0064] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 2 mol;

[0065] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0066] S3: Place the intermediate product II, mercaptopropionic acid, and tetrabutylammonium bromide in a three-necked flask, stir at 110°C for 2 hours, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and then wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it over anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0067] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0068] The ratio of the intermediate product II and mercaptopropionic acid is 1.5 mol:1 mol based on the epoxy group:carboxyl group;

[0069] The amount of tetrabutylammonium bromide used was 1.5% of the total mass of the reactants.

[0070] Its infrared data is as follows: 3383cm -1 :-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0071] Example 3

[0072] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0073] S1: Add cardanol, oleic acid, hypophosphorous acid, and methylhydroquinone to xylene, heat to 180°C and vigorously stir for 2 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0074] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.2 mol: 200 mL: 500 mL: 500 mL;

[0075] The amount of hypophosphorous acid used is 1% of the total mass of the reactants;

[0076] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0077] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0078] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 60°C, and begin dropwise addition of hydrogen peroxide. React for 5 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, take the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0079] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 3 mol;

[0080] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0081] S3: Place the intermediate product II, mercaptopropionic acid, and N,N-dimethylbenzylamine in a three-necked flask, stir at 110°C for 2 hours, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0082] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0083] The ratio of the intermediate product II and mercaptopropionic acid is 2 mol:1 mol based on the epoxy group:carboxyl group;

[0084] The amount of N,N-dimethylbenzylamine used is 1.5% of the total mass of the reactants.

[0085] Its infrared data is as follows: 3383cm -1:-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0086] Example 4

[0087] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0088] S1: Add cardanol, oleic acid, p-toluenesulfonic acid, and methylhydroquinone to xylene, heat to 160°C, vigorously stir for 3 hours, let stand, cool to room temperature, and vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution to wash three times, wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0089] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.2 mol: 200 mL: 500 mL: 500 mL;

[0090] The amount of p-toluenesulfonic acid used is 1% of the total mass of the reactants;

[0091] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0092] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0093] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 65°C, and begin dropwise addition of hydrogen peroxide. React for 4 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, take the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0094] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0095] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0096] S3: Place the intermediate product II, mercaptopropionic acid, and triphenylphosphine in a three-necked flask, stir at 100°C for 3 hours, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it over anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0097] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0098] The ratio of the intermediate product II and mercaptopropionic acid is 3 mol:1 mol based on the epoxy group:carboxyl group;

[0099] The amount of triphenylphosphine used was 1.5% of the total mass of the reactants.

[0100] Its infrared data is as follows: 3383cm -1 :-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0101] Example 5

[0102] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0103] S1: Add cardanol, oleic acid, tetrabutyl titanate, and methylhydroquinone to xylene, heat to 160°C and vigorously stir for 2 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0104] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.1 mol: 200 mL: 500 mL: 500 mL;

[0105] The amount of tetrabutyl titanate used is 1% of the total mass of the reactants;

[0106] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0107] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0108] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 65°C, and begin dropwise addition of hydrogen peroxide. React for 3 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, and remove the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0109] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0110] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0111] S3: Place the intermediate product II, mercaptopropionic acid, and triphenylphosphine in a three-necked flask, stir at 100°C for 1 hour, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it over anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0112] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0113] The ratio of the intermediate product II and mercaptopropionic acid is 4 mol:1 mol based on the epoxy group:carboxyl group;

[0114] The amount of triphenylphosphine used is 1.5% of the total mass of the reactants.

[0115] Its infrared data is as follows: 3383cm -1 :-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0116] Example 6

[0117] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0118] S1: Add cardanol, oleic acid, hypophosphorous acid, and methylhydroquinone to xylene, heat to 180°C and vigorously stir for 3 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0119] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.1 mol: 200 mL: 500 mL: 500 mL;

[0120] The amount of hypophosphorous acid used is 1% of the total mass of the reactants;

[0121] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0122] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0123] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 60°C, and begin dropwise addition of hydrogen peroxide. React for 3 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, and remove the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0124] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0125] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0126] S3: Place the intermediate product II, mercaptopropionic acid, and triphenylphosphine in a three-necked flask, stir at 120°C for 2 hours, cool to room temperature, add dichloromethane for extraction, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III, i.e., PVC plasticizer;

[0127] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0128] The ratio of the intermediate product II and mercaptopropionic acid is 3.5 mol:1 mol based on the epoxy group:carboxyl group;

[0129] The amount of triphenylphosphine used was 1.5% of the total mass of the reactants.

[0130] Its infrared data is as follows: 3383cm -1:-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0131] Example 7

[0132] This embodiment provides a method for preparing a PVC plasticizer, comprising the following steps:

[0133] S1: Add cardanol, oleic acid, p-toluenesulfonic acid, and methylhydroquinone to xylene, heat to 170°C and vigorously stir for 2 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0134] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.2 mol: 200 mL: 500 mL: 500 mL;

[0135] The amount of p-toluenesulfonic acid used is 1% of the total mass of the reactants;

[0136] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0137] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0138] S2: Add intermediate product I, glacial acetic acid, and toluene to a three-necked flask, stir magnetically, heat to 60°C, and begin dropwise addition of hydrogen peroxide. React for 6 h, cool to room temperature, wash with deionized water until neutral, separate the liquids, and remove the organic phase, evaporate under reduced pressure, and dry in a vacuum at 60°C for 4 h to obtain intermediate product II.

[0139] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0140] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0141] S3: Place the intermediate product II, mercaptopropionic acid, and triphenylphosphine in a three-necked flask, stir at 130°C for 2 hours, cool to room temperature, extract with dichloromethane, wash three times with a 2 wt% sodium bicarbonate aqueous solution, and then wash with deionized water until neutral. Separate the liquids, take the organic phase, dry it over anhydrous sodium sulfate for 6 hours, filter it, take the filtrate, distill it under reduced pressure, and dry it in a vacuum at 60°C for 4 hours to obtain the target product III;

[0142] The ratio of intermediate product II, dichloromethane, 2 wt% sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 400 mL: 500 mL: 500 mL;

[0143] The ratio of the intermediate product II and mercaptopropionic acid is 2.5 mol:1 mol based on the epoxy group:carboxyl group;

[0144] The amount of triphenylphosphine used was 1.5% of the total mass of the reactants.

[0145] Its infrared data is as follows: 3383cm -1 :-OH exists; 1773cm -1 :-C=O exists and is enhanced; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 943cm -1 、824cm -1 :Epoxy groups exist and weaken; 2551cm -1 :-SH exists.

[0146] The PVC plasticizer prepared in the above embodiment is used as the basic material of the application embodiment to make a PVC film.

[0147] Application Example 1

[0148] A PVC sample is composed of the following raw materials in parts by weight:

[0149] PVC SG-5 100 parts;

[0150] 40 parts of PVC plasticizer.

[0151] The raw material components of the PVC samples in Application Examples 2-7 are the same as those in Application Example 1, except that the PVC plasticizers prepared in the corresponding Examples 2-7 are used in sequence.

[0152] The preparation method of a PVC sheet in the above application examples 1-7 comprises the following steps:

[0153] The above raw materials were mixed evenly, plasticized on a double-roll mill at 170°C for 15 minutes, and then pressed into sheets using a flat vulcanizer.

[0154] The weight ratio of cardanol, oleic acid and mercaptopropionic acid in the raw material components of the PVC plasticizer in the above application example is 7.7-7.9 / 7.2-7.4 / 1.

[0155] Comparative Application Example 1

[0156] This comparative example provides a PVC sheet, which is composed of the following raw materials in parts by weight:

[0157] PVC SG-5 100 parts;

[0158] DOTP 40 copies.

[0159] Application Comparative Example 2

[0160] A PVC sheet is composed of the following raw materials in parts by weight:

[0161] PVC SG-5 100 parts;

[0162] DOTP 40 copies;

[0163] 2.5 parts of calcium zinc stabilizer.

[0164] Application Comparative Example 3

[0165] A PVC sheet is composed of the following raw materials in parts by weight:

[0166] PVC SG-5 100 parts;

[0167] 40 parts of epoxy cardanol.

[0168] Comparative Application Example 4

[0169] A PVC sheet is composed of the following raw materials in parts by weight:

[0170] PVC SG-5 100 parts;

[0171] 37.5 parts of epoxy cardanol;

[0172] 2.5 parts of mercaptopropionic acid.

[0173] Comparative Application Example 5

[0174] A PVC sheet is composed of the following raw materials in parts by weight:

[0175] PVC SG-5 100 parts;

[0176] 19.5 parts of epoxy cardanol;

[0177] 18 parts of oleic acid;

[0178] 2.5 parts of mercaptopropionic acid.

[0179] Application Comparative Example 6

[0180] A PVC sheet is composed of the following raw materials in parts by weight:

[0181] PVC SG-5 100 parts;

[0182] 40 parts of epoxy cardanol ester.

[0183] Application Comparative Example 7

[0184] A PVC sheet is composed of the following raw materials in parts by weight:

[0185] PVC SG-5 100 parts;

[0186] 37.5 parts of epoxy cardanol ester;

[0187] 2.5 parts of mercaptopropionic acid.

[0188] The preparation method of the epoxy cardanol in the above comparative application example is as follows:

[0189] Add cardanol, glacial acetic acid, and toluene into a three-necked flask, stir magnetically, heat to 60°C, begin to dropwise add hydrogen peroxide, react for 6 hours, cool to room temperature, wash with deionized water until neutral, separate the liquids, take the organic phase, distill under reduced pressure, and dry in vacuo at 60°C for 4 hours to obtain epoxy cardanol;

[0190] The usage ratio of cardanol, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0191] Its infrared data are as follows: 3371cm-1: presence of phenol-OH; 3010cm-1: presence of benzene ring -CH, 1589cm-1: presence of benzene ring -C=C-; 1639cm-1, 817cm-1: disappearance of -C=C-; 943cm-1, 824cm-1: presence of epoxy group.

[0192] The preparation method of the epoxy cardanol ester in the above comparative example is as follows:

[0193] S1: Add cardanol, oleic acid, p-toluenesulfonic acid, and methylhydroquinone to xylene, heat to 170°C and vigorously stir for 3 hours, let stand, cool to room temperature, and then vacuum concentrate the solution to enrich the residual components; slowly add 2 wt% sodium bicarbonate aqueous solution to wash three times, wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate for 6 hours, filter, and dry the filtrate at 60°C in vacuum for 4 hours to obtain intermediate product I;

[0194] The dosage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is: 1 mol: 1.1 mol: 200 mL: 500 mL: 500 mL;

[0195] The amount of p-toluenesulfonic acid used is 1% of the total mass of the reactants;

[0196] The amount of methylhydroquinone used is 0.5% of the total mass of the reactants;

[0197] Its infrared data are as follows: 3351cm -1 :-OH disappears; 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- exists.

[0198] S2: Add intermediate product I, glacial acetic acid, and toluene into a three-necked flask, stir magnetically, heat to 60°C, begin to add hydrogen peroxide dropwise, react for 6 hours, cool to room temperature, wash with deionized water until neutral, separate the liquids, take the organic phase, distill under reduced pressure, and dry in a vacuum at 60°C for 4 hours to obtain intermediate product II, i.e., epoxy cardanol ester;

[0199] The usage ratio of intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is: 1 mol: 4 mol: 400 mL: 4 mol;

[0200] Its infrared data are as follows: 1773cm -1 :-C=O exists; 3010cm -1 : Benzene ring-CH, 1589cm -1 : benzene ring -C=C- exists; 1639cm -1 、817cm -1 :-C=C- disappears; 943cm -1 、824cm -1 : Epoxy groups are present.

[0201] The preparation method of the PVC sheet in the above comparative application examples 1-7 comprises the following steps:

[0202] The above raw materials were mixed evenly, plasticized on a double-roll mill at 170°C for 15 minutes, and then pressed into sheets on a flat vulcanizer.

[0203] The physical properties of the PVC sheets prepared in Application Examples 1-7 and Comparative Application Examples 1-7 of the present invention were measured respectively, and the results are shown in Table 1.

[0204] The test method is as follows:

[0205] (1) Glass transition temperature: Dynamic mechanical properties tests were performed on a DMA-Q800 dynamic mechanical analyzer using a dual cantilever beam mode. The test frequency was 1 Hz, the heating rate was 3°C / min, and the test temperature range was -60-80°C. Each sample was tested repeatedly.

[0206] (2) Elongation at break and tensile strength test: The test was carried out on a universal testing machine at a test rate of 10 mm / min and a test temperature of 23°C. The test data was the average value of 5 parallel samples.

[0207] (3) Appearance color: Observe the final color of the sample after leaving the roller with the naked eye. Apparent color representation method: 5 is the lightest color, i.e. the best; 1 is the darkest color, i.e. the worst.

[0208] (4) Yellowness index: The tristimulus values ​​X, Y, and Z of different samples before and after aging were tested using a YI-48A whiteness colorimeter according to GB2409 standard. The yellowness index of the film samples before and after aging was calculated by the following formula:

[0209] YI=[100×(1.28X-1.06Z)] / Y

[0210] (ΔYI n =YI n -YI0 Where: ΔYI n : Yellowness index change after sample aging for n days; YI0 and YI n The yellowness index values ​​of the membrane sample before aging and after aging for n days are shown in Figure 2. ) The test duration for this experiment is n = 20 days.

[0211] (5) Migration Performance: The PVC film was placed in a UV aging test chamber for 20 days. After removal, the film was rinsed with acetonitrile. The eluent was collected and the UV-visible spectrum was measured at a wavelength of 200-500 nm. The migration performance was expressed as follows: 5 represents the lowest molar absorption coefficient, i.e., the best migration performance; 1 represents the highest molar absorption coefficient, i.e., the worst migration performance.

[0212] Table 1

[0213]

[0214] As can be seen from Table 1, the PVC samples prepared using the PVC plasticizer prepared by the present invention in Application Examples 1-7 all have a low glass transition temperature and excellent mechanical properties. The reasons for this may be: first, although the molecular weight of the PVC plasticizer provided by the present invention is larger than that of DOTP, it still belongs to a small molecule structure and has excellent dispersibility; second, in addition to having a structure similar to DOTP, the PVC plasticizer provided by the present invention has a longer molecular chain, which is more effective in removing the intermolecular forces of PVC and has lubricating plasticizing properties; third, it also has epoxy, hydroxyl, and thiol structures that couple with Cl in PVC, changing the strong force to weak force, giving it better plasticizing properties, and therefore its glass transition temperature is lower; fourth, the presence of ester groups, epoxy groups, thiol groups, and hydroxyl groups provides excellent thermal stability, which greatly improves the mechanical properties of the product. The PVC plasticizer prepared in Example 1-7 is used to prepare PVC samples having good appearance and low migration. It is speculated that the reason may be that the presence of ester, epoxy, thiol, and hydroxyl groups in the PVC plasticizer provided by the present invention gives it excellent thermal stability, and the thiol group undergoes a "thiol-ene" click reaction with the double bond generated by the decomposition of PVC, and the plasticizer is chemically bonded to the PVC main resin, resulting in excellent low migration and safe and green characteristics.

[0215] In summary, the PVC plasticizer provided by the present invention has advantages in glass transition temperature, mechanical properties, appearance, and migration after being applied in Application Examples 1-7. The reason is that the chemically modified structure has excellent functional orientation and its comprehensive performance is significantly better than that of the physical compound, that is, it has better plasticity and thermal stability and does not migrate.

[0216] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A PVC plasticizer, characterized in that The PVC plasticizer is prepared by the following method: S1: Add cardanol, oleic acid, catalyst A, and methylhydroquinone to xylene, heat to 150-180°C, stir for 2-3 hours, let stand, cool to room temperature, and vacuum concentrate the solution; add sodium bicarbonate aqueous solution and wash three times, then wash with deionized water until neutral, separate the liquids, take the organic phase, dry it with anhydrous sodium sulfate, filter, and dry the filtrate in vacuum at 60°C to obtain intermediate product I; S2: The intermediate product I, glacial acetic acid, and toluene were added to a three-necked flask, stirred magnetically, and heated to 60-65°C. Hydrogen peroxide was added dropwise and reacted for 3-6 hours. The mixture was cooled to room temperature and washed with deionized water until neutral. The organic phase was separated and distilled under reduced pressure and dried under vacuum at 60°C for 4 hours to obtain the intermediate product II. S3: The intermediate product II, mercaptopropionic acid, and catalyst B were placed in a three-necked flask, stirred at 100-130°C, cooled to room temperature, extracted with dichloromethane, washed three times with sodium bicarbonate aqueous solution, and then washed with deionized water until neutral. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and the filtrate was distilled under reduced pressure and dried in vacuo at 60°C for 4 hours to obtain a PVC plasticizer; The catalyst A is selected from at least one of p-toluenesulfonic acid, tetrabutyl titanate, and hypophosphorous acid; The catalyst B is selected from at least one of triphenylphosphine, tetrabutylammonium bromide, and N,N-dimethylbenzylamine.

2. The PVC plasticizer according to claim 1, wherein The mass concentration of the sodium bicarbonate aqueous solution in step S1 is 2 wt %; the usage ratio of cardanol, oleic acid, xylene, sodium bicarbonate aqueous solution, and deionized water is 1 mol: (1-1.2) mol: 200 mL: 500 mL: 500 mL.

3. The PVC plasticizer according to claim 2, wherein The amount of the catalyst A used is 1% of the total mass of the reactants in step S1; the amount of the methylhydroquinone used is 0.5% of the total mass of the reactants in step S1.

4. The PVC plasticizer according to claim 1, wherein In step S2, the usage ratio of the intermediate product I, glacial acetic acid, toluene, and hydrogen peroxide is 1 mol:4 mol:400 mL:(2-4) mol.

5. The PVC plasticizer according to claim 1, wherein The mass concentration of the sodium bicarbonate aqueous solution in step S3 is 2 wt %; the usage ratio of the intermediate product II, dichloromethane, the sodium bicarbonate aqueous solution, and deionized water is 1 mol:400 mL:500 mL:500 mL.

6. The PVC plasticizer according to claim 5, wherein In step S3, the intermediate product II and mercaptopropionic acid are used in a ratio of (1.5-4) mol to 1 mol of epoxy group and carboxyl group.

7. The PVC plasticizer according to claim 5, wherein The amount of catalyst B used is 1.5% of the total mass of the reactants in step S3.

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