Highly impermeable PVC / PVDC composite hard sheet and method for preparing the same

Abstract

This invention discloses a high-barrier PVC / PVDC composite rigid sheet and its preparation method, relating to the field of packaging materials technology. In this invention, an anti-UV derivative is prepared by reacting 4-fluoro-4'-hydroxybenzophenone with cyanuric chloride, then reacted with 1H-benzimidazole-5-carboxaldehyde to introduce an aldehyde group, and finally condensed with a primary amino aldehyde amine of 1,10-diaminodecane to obtain a terminal amino macromolecular UV absorber. This invention also introduces quaternary ammonium groups into the molecular chain of epoxidized soybean oil to obtain quaternized epoxidized soybean oil. The amino groups of the terminal amino macromolecular UV absorber connect the epoxy resin and the quaternized epoxidized soybean oil, reducing the risk of phase separation. This results in the PVC substrate after compression curing possessing both anti-UV groups and antibacterial quaternary ammonium salt groups, endowing the PVC / PVDC composite rigid sheet with antibacterial properties and improving aging resistance, allowing the composite rigid sheet to maintain good barrier performance even after irradiation.

Description

Technical Field

[0001] This invention relates to the field of packaging materials technology, specifically to a high-barrier PVC / PVDC composite rigid sheet and its preparation method. Background Technology

[0002] Plastic products are widely used due to their advantages such as lightness, corrosion resistance, and low cost, and are also the mainstream solution for pharmaceutical packaging. Among existing technologies, PVC / PVDC composite rigid sheets are one of the most widely used packaging materials. PVC has good processing performance, and PVDC has high barrier properties, making it difficult for water molecules to penetrate and ensuring the quality of pharmaceuticals. Combining the advantages of both can improve the barrier performance of composite rigid sheets.

[0003] Patent CN202210987241.4 discloses a manufacturing process for PVC solid pharmaceutical composite rigid sheets, which obtains PVC composite rigid sheets by coating an adhesive and PVDC emulsion onto a PVC substrate. However, the PVC surface lacks antibacterial groups, making it prone to the growth of microorganisms, which leads to a decline in material performance and may even cause health problems. Furthermore, PVC has poor aging resistance and is easily denatured by ultraviolet radiation, resulting in yellowing and reducing the barrier properties of the composite rigid sheet.

[0004] Therefore, this application improves the barrier properties by preparing a composite hard sheet with excellent antibacterial and UV resistance properties, thereby enhancing its antibacterial and aging resistance properties. Summary of the Invention

[0005] The purpose of this invention is to provide a high-barrier PVC / PVDC composite rigid sheet and its preparation method, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-barrier PVC / PVDC composite rigid sheet, comprising a PVC substrate layer and a PVDC layer; The PVC substrate layer includes ultraviolet absorbing groups and antibacterial groups.

[0007] Furthermore, the PVDC layer is disposed on one side surface of the PVC substrate layer; An adhesive layer is provided between the PVC substrate layer and the PVDC layer.

[0008] A method for preparing a high-barrier PVC / PVDC composite rigid sheet includes the following processes: Take a PVC substrate, coat one side of it with an adhesive, dry it to form an adhesive layer, then coat it with a PVDC emulsion, dry it to form a PVDC layer, and cure it to obtain a PVC / PVDC composite rigid sheet.

[0009] Furthermore, the thickness of the PVC substrate is 0.35~0.45mm.

[0010] Furthermore, the adhesive is a polyurethane adhesive, and the coating amount of the adhesive is 1~3 g / m². 2 ; The coating amount of the PVDC emulsion is 8~12 g / m³. 2 .

[0011] Furthermore, the PVC substrate is subjected to corona treatment before the adhesive is applied. The specific process conditions are: voltage 10~15KV, distance between the electrode and the PVC substrate 2~6mm, and pulse frequency 10~15KHz.

[0012] Furthermore, the drying process conditions are: temperature 60~70℃, time 5~10min; The curing process conditions are: temperature 25~35℃, time 24~48h.

[0013] Furthermore, the PVC substrate is obtained by the following process: Step 1: Mix epoxy resin and quaternized epoxidized soybean oil evenly, heat to 50~60℃, add terminal amino macromolecular ultraviolet absorber and stir evenly to obtain mixed slurry; Step 2: Mix PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry, then knead, press into sheets and heat-cur to obtain PVC substrate.

[0014] Furthermore, in step 1, the mass ratio of epoxy resin, quaternized epoxidized soybean oil, and terminal amino macromolecular ultraviolet absorber is (1~4):(1~4):(0.25~1.0).

[0015] Furthermore, in step 2, the mass ratio of PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry is 10: (0.5~0.6): (1.2~1.6): (1.5~2.5).

[0016] Furthermore, in step 2, the mixing process conditions are: temperature 170~180℃, time 10~15min; The tableting process conditions are: temperature 160~180℃, time 3~5min; The process conditions for heat preservation and curing are: temperature 130~140℃, time 3~4h.

[0017] Furthermore, the quaternized epoxidized soybean oil is obtained by the following process: Step 1.1: Mix N,N-dimethyl-11-aminoundecanoic acid and triphenylphosphine evenly, then add epoxidized soybean oil, and heat the mixture under a nitrogen atmosphere to obtain tertiary amination epoxidized soybean oil; Step 1.2: N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane are mixed, microwave reaction is carried out, and vacuum distillation is performed to obtain quaternized ammonium epoxidized soybean oil.

[0018] Furthermore, in step 1.1, the mass ratio of N,N-dimethyl-11-aminoundecanoic acid, triphenylphosphine, and epoxidized soybean oil is (0.9~1.2):(0.01~0.05):(1.0~1.2).

[0019] Furthermore, in step 1.1, the process conditions for the heating reaction are: temperature 100~110℃, time 3~5h.

[0020] Furthermore, in step 1.2, the mass ratio of N,N-dimethylformamide, tertiary amination epoxidized soybean oil, and 1-chlorododecane is 8:1:(0.5~1.0).

[0021] Furthermore, in step 1.2, the process conditions for the microwave reaction are: power 600~700W, temperature 130~140℃, and time 2~4h.

[0022] Furthermore, in step 1.2, the process conditions for vacuum distillation are: vacuum degree -0.098~-0.10MPa, temperature 90~100℃, and time 1~2h.

[0023] In the above technical solution, the carboxyl group of N,N-dimethyl-11-aminoundecanoic acid and the epoxy group of epoxidized soybean oil are ring-opened under the action of triphenylphosphine to form an ester bond and a new hydroxyl group, while a tertiary amine group is introduced to obtain tertiary amination epoxidized soybean oil. Then, 1-chlorododecane undergoes nucleophilic substitution with the tertiary amination epoxidized soybean oil to obtain quaternized epoxidized soybean oil. Unmodified epoxidized soybean oil has weak polarity, while epoxy resin is a strongly polar substance, resulting in poor compatibility between the two. This invention modifies epoxidized soybean oil by introducing hydroxyl groups, ester bonds, and quaternary ammonium salt groups into its molecular chain, thereby enhancing the polarity of the epoxidized soybean oil and improving its compatibility with epoxy resin. Furthermore, by controlling the amount of N,N-dimethyl-11-aminoundecanoic acid added, some epoxy groups are retained, enabling cross-linking with epoxy resin through terminal amino macromolecular UV absorbers, reducing the risk of phase separation. In addition, quaternary ammonium salt groups have broad-spectrum antibacterial properties, so the PVC substrate obtained after quaternized epoxidized soybean oil is mixed with PVC granules and pressed also has antibacterial properties. 1-Chlorododecane has a long-chain alkyl group, which can further improve the toughness of the prepared quaternized epoxidized soybean oil and improve the mechanical properties of the PVC substrate.

[0024] Furthermore, the preparation process of the terminal amino macromolecular ultraviolet absorber is as follows: S1: Mix cyanuric chloride and acetone, stir evenly at 0~5℃, add 4-fluoro-4'-hydroxybenzophenone solution and NaOH aqueous solution, react in an ice-water bath, filter and wash after the reaction to obtain the anti-ultraviolet derivative; S2: Tetrahydrofuran, UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine are mixed and heated to react, yielding an aldehyde-terminated UV-resistant derivative. S3: Anhydrous ethanol, terminal aldehyde UV absorber derivative, 1,10-diaminodecane, and glacial acetic acid are mixed evenly and heated under a nitrogen atmosphere. After the reaction is completed, the mixture is filtered, washed, and dried to obtain a terminal amino macromolecular UV absorber.

[0025] Furthermore, in S1, the ratio of cyanuric chloride, acetone, 4-fluoro-4'-hydroxybenzophenone solution and NaOH aqueous solution is 1g: (7~10)mL: (6~8)mL: 50mL.

[0026] Furthermore, the 4-fluoro-4'-hydroxybenzophenone solution is obtained by mixing 4-fluoro-4'-hydroxybenzophenone and acetone at a ratio of 1g:(8~10)mL; The concentration of the NaOH aqueous solution is 0.2~0.3 mol / L.

[0027] Furthermore, in S1, the process conditions for the ice-water bath reaction are: temperature 0~5℃, time 4~5h.

[0028] Furthermore, in S2, the mass ratio of tetrahydrofuran, the UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine is 100:10:(10~16):(5~7).

[0029] Furthermore, in S2, the process conditions for the heating reaction are: temperature 60~70℃, time 1~3h.

[0030] Furthermore, in S3, the mass ratio of anhydrous ethanol, terminal aldehyde UV-resistant derivative, 1,10-diaminodecane, and glacial acetic acid is 100:10:(12~16):(0.5~1.0).

[0031] Furthermore, in S3, the process conditions for the heating reaction are: temperature 80~90℃, time 12~18h.

[0032] In the above technical solution, 4-fluoro-4'-hydroxybenzophenone is first used as a nucleophile to attack the chlorine atom of cyanuric chloride, while retaining the other two chlorine atoms to obtain an anti-UV derivative. Then, 1H-benzimidazole-5-carboxaldehyde is used as a nucleophile, and its secondary amino group reacts with the two chlorine atoms in the anti-UV derivative to introduce an aldehyde group, thus obtaining a terminal aldehyde anti-UV derivative. Finally, in a weakly acidic environment, the aldehyde group undergoes aldehyde-amine condensation with the primary amino group of 1,10-diaminodecane, while retaining the other primary amino group, to obtain a terminal amino macromolecular UV absorber. The benzophenone and benzimidazole groups in the aforementioned terminal amino macromolecular UV absorbers both possess excellent UV protection properties. Their synergistic effect can broaden the UV absorption range (UV-A and UV-B) and improve the UV shielding rate. The terminal amino groups can connect epoxy resin with quaternized epoxidized soybean oil, grafting the UV-protective groups onto the polymer chain segments and reducing the risk of precipitation. In addition, 1,10-diaminodecane has long-chain alkyl groups, which can improve the toughness of the PVC substrate. 4-fluoro-4'-hydroxybenzophenone contains fluorine and has a certain degree of hydrophobicity, which can further reduce the water vapor transmission rate of the composite rigid sheet.

[0033] Compared with the prior art, the beneficial effects of the present invention are: 1. Unmodified epoxidized soybean oil has weak polarity, while epoxy resin is a strongly polar substance, resulting in poor compatibility between the two. This invention modifies epoxidized soybean oil by introducing hydroxyl groups, ester bonds, and quaternary ammonium salt groups into its molecular chain, thereby enhancing the polarity of the epoxidized soybean oil and improving its compatibility with epoxy resin. Furthermore, by controlling the amount of N,N-dimethyl-11-aminoundecanoic acid added, some epoxy groups are retained, enabling cross-linking with epoxy resin through terminal amino macromolecular UV absorbers, reducing the risk of phase separation. In addition, quaternary ammonium salt groups have broad-spectrum antibacterial properties, so the PVC substrate obtained after quaternized epoxidized soybean oil is mixed with PVC granules and pressed also has antibacterial properties. 1-Chlorododecane has long-chain alkyl groups, which can further improve the toughness of the prepared quaternized epoxidized soybean oil and improve the mechanical properties of the PVC substrate.

[0034] 2. In this invention, both the benzophenone group and the benzimidazole group in the terminal amino macromolecular ultraviolet absorber have excellent anti-ultraviolet properties. The two work synergistically to broaden the ultraviolet absorption range (UV-A and UV-B) and improve the ultraviolet shielding rate. The terminal amino group can connect the epoxy resin with the quaternized epoxidized soybean oil, grafting the anti-ultraviolet group onto the polymer chain segment and reducing the risk of precipitation. In addition, 1,10-diaminodecane has a long-chain alkyl group, which can improve the toughness of the PVC substrate. 4-fluoro-4'-hydroxybenzophenone contains fluorine and has a certain degree of hydrophobicity, which can further reduce the water vapor transmission rate of the composite rigid sheet. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the following specific implementation, PVDC emulsion, brand name A736; Polyurethane adhesive, model DZ3023; Epoxy resin, model YN1828; PVC granules, grade S-65; Acetate chlorination resin, model 4508; Epoxidized soybean oil, molecular weight 950, epoxy value ≥6.0%.

[0037] Example 1: A method for preparing a high-barrier PVC / PVDC composite rigid sheet, comprising the following steps: (1) Preparation of terminal amino macromolecular ultraviolet absorbers: S1: Cyanurium chloride and acetone are mixed and stirred evenly at 0℃. A solution of 4-fluoro-4'-hydroxybenzophenone and an aqueous solution of NaOH are added, and the mixture is reacted in an ice-water bath. After the reaction, the mixture is filtered and washed to obtain the UV-resistant derivative. S2: Tetrahydrofuran, the UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine are mixed and heated to obtain the aldehyde-terminated UV-resistant derivative. S3: Anhydrous ethanol, the aldehyde-terminated UV-resistant derivative, 1,10-diaminodecane, and glacial acetic acid are mixed evenly and heated under a nitrogen atmosphere. After the reaction, the mixture is filtered, washed, and dried to obtain the amine-terminated macromolecular UV absorber. In S1, the ratio of cyanurium chloride, acetone, 4-fluoro-4'-hydroxybenzophenone solution, and NaOH aqueous solution is 1g:10mL. 8 mL: 50 mL; the 4-fluoro-4'-hydroxybenzophenone solution was obtained by mixing 4-fluoro-4'-hydroxybenzophenone and acetone at a ratio of 1 g: 10 mL; the concentration of the NaOH aqueous solution was 0.3 mol / L; in S1, the process conditions for the ice-water bath reaction were: temperature 0℃, time 5 h; in S2, the mass ratio of tetrahydrofuran, anti-UV derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine was 100:10:16:7; in S2, the process conditions for the heating reaction were: temperature 70℃, time 3 h; in S3, the mass ratio of anhydrous ethanol, terminal aldehyde anti-UV derivative, 1,10-diaminodecane, and glacial acetic acid was 100:10:16:1.0; in S3, the process conditions for the heating reaction were: temperature 90℃, time 18 h; (2) Preparation of quaternized epoxidized soybean oil: Step 1.1: N,N-dimethyl-11-aminoundecanoic acid and triphenylphosphine are mixed evenly, then epoxidized soybean oil is added. The mixture is heated under a nitrogen atmosphere to obtain tertiary amination epoxidized soybean oil. Step 1.2: N,N-dimethylformamide, tertiary amination epoxidized soybean oil, and 1-chlorododecane are mixed and subjected to microwave reaction followed by vacuum distillation to obtain quaternized epoxidized soybean oil. In Step 1.1, the mass ratio of N,N-dimethyl-11-aminoundecanoic acid, triphenylphosphine, and epoxidized soybean oil is 1:1. .2:0.05:1.2; In step 1.1, the heating reaction conditions are: temperature 110℃, time 5h; In step 1.2, the mass ratio of N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane is 8:1:1.0; In step 1.2, the microwave reaction conditions are: power 700W, temperature 140℃, time 4h; In step 1.2, the vacuum distillation conditions are: vacuum degree -0.10MPa, temperature 100℃, time 2h; (3) Preparation of PVC substrate: Step 1: Mix epoxy resin and quaternized epoxidized soybean oil evenly, heat to 60℃, add terminal amino macromolecular UV absorber and stir evenly to obtain a mixed slurry; Step 2: Mix PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and the mixed slurry, knead, press, and heat-cur to obtain PVC substrate; In Step 1, the mass ratio of epoxy resin, quaternized epoxidized soybean oil and terminal amino macromolecular UV absorber is 4:4:1.0; In Step 2, the mass ratio of PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry is 10:0.6:1.6:2.5; In Step 2, the kneading process conditions are: temperature 180℃, time 15min; the pressing process conditions are: temperature 180℃, time 5min; the heat-curing process conditions are: temperature 140℃, time 4h; (4) Preparation of PVC / PVDC composite rigid sheets: Take a PVC substrate, coat one side of it with adhesive, dry it to form an adhesive layer, then coat it with PVDC emulsion, dry it to form a PVDC layer, and cure it to obtain a PVC / PVDC composite rigid sheet; the thickness of the PVC substrate is 0.45 mm; the coating amount of adhesive is 3 g / m². 2 The coating amount of PVDC emulsion is 12 g / m². 2 The PVC substrate was subjected to corona treatment before the adhesive was applied. The specific process conditions were: voltage 15KV, distance between the electrode and the PVC substrate 6mm, and pulse frequency 15KHz. The drying process conditions were: temperature 70℃ and time 10min. The curing process conditions were: temperature 35℃ and time 48h.

[0038] Example 2: A method for preparing a high-barrier PVC / PVDC composite rigid sheet, comprising the following steps: (1) Preparation of terminal amino macromolecular ultraviolet absorbers: S1: Cyanurium chloride and acetone are mixed and stirred evenly at 3°C. A solution of 4-fluoro-4'-hydroxybenzophenone and an aqueous solution of NaOH are added, and the mixture is reacted in an ice-water bath. After the reaction, the mixture is filtered and washed to obtain the UV-resistant derivative. S2: Tetrahydrofuran, the UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine are mixed and heated to obtain the aldehyde-terminated UV-resistant derivative. S3: Anhydrous ethanol, the aldehyde-terminated UV-resistant derivative, 1,10-diaminodecane, and glacial acetic acid are mixed evenly and heated under a nitrogen atmosphere. After the reaction, the mixture is filtered, washed, and dried to obtain the amine-terminated macromolecular UV absorber. In S1, the ratio of cyanurium chloride, acetone, 4-fluoro-4'-hydroxybenzophenone solution, and NaOH aqueous solution is 1 g: 8 mL. 7 mL: 50 mL; the 4-fluoro-4'-hydroxybenzophenone solution was obtained by mixing 4-fluoro-4'-hydroxybenzophenone and acetone at a ratio of 1 g: 9 mL; the concentration of the NaOH aqueous solution was 0.2 mol / L; in S1, the process conditions for the ice-water bath reaction were: temperature 3℃, time 4 h; in S2, the mass ratio of tetrahydrofuran, anti-UV derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine was 100:10:13:6; in S2, the process conditions for the heating reaction were: temperature 65℃, time 2 h; in S3, the mass ratio of anhydrous ethanol, terminal aldehyde anti-UV derivative, 1,10-diaminodecane, and glacial acetic acid was 100:10:14:0.8; in S3, the process conditions for the heating reaction were: temperature 85℃, time 16 h; (2) Preparation of quaternized epoxidized soybean oil: Step 1.1: N,N-dimethyl-11-aminoundecanoic acid and triphenylphosphine are mixed evenly, then epoxidized soybean oil is added. The mixture is heated under a nitrogen atmosphere to obtain tertiary amination epoxidized soybean oil. Step 1.2: N,N-dimethylformamide, tertiary amination epoxidized soybean oil, and 1-chlorododecane are mixed and subjected to microwave reaction followed by vacuum distillation to obtain quaternized epoxidized soybean oil. In Step 1.1, the mass ratio of N,N-dimethyl-11-aminoundecanoic acid, triphenylphosphine, and epoxidized soybean oil is 1:1. 0:0.03:1.1; In step 1.1, the heating reaction conditions are: temperature 105℃, time 4h; In step 1.2, the mass ratio of N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane is 8:1:0.8; In step 1.2, the microwave reaction conditions are: power 650W, temperature 135℃, time 3h; In step 1.2, the vacuum distillation conditions are: vacuum degree -0.099MPa, temperature 95℃, time 1h; (3) Preparation of PVC substrate: Step 1: Mix epoxy resin and quaternized epoxidized soybean oil evenly, heat to 55℃, add terminal amino macromolecular UV absorber and stir evenly to obtain a mixed slurry; Step 2: Mix PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and the mixed slurry, knead, press, and heat-cur to obtain PVC substrate; In Step 1, the mass ratio of epoxy resin, quaternized epoxidized soybean oil and terminal amino macromolecular UV absorber is 2:3:0.75; In Step 2, the mass ratio of PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry is 10:0.5:1.4:2.0; In Step 2, the kneading process conditions are: temperature 175℃, time 13min; the pressing process conditions are: temperature 170℃, time 4min; the heat-curing process conditions are: temperature 135℃, time 3h; (4) Preparation of PVC / PVDC composite rigid sheets: Take a PVC substrate, coat one side of it with adhesive, dry it to form an adhesive layer, then coat it with PVDC emulsion, dry it to form a PVDC layer, and cure it to obtain a PVC / PVDC composite rigid sheet; the thickness of the PVC substrate is 0.40 mm; the coating amount of adhesive is 2 g / m². 2 The coating amount of PVDC emulsion is 10 g / m². 2 The PVC substrate was subjected to corona treatment before the adhesive was applied. The specific process conditions were: voltage 13KV, distance between the electrode and the PVC substrate 4mm, and pulse frequency 13KHz. The drying process conditions were: temperature 65℃ and time 8min. The curing process conditions were: temperature 30℃ and time 36h.

[0039] Example 3: A method for preparing a high-barrier PVC / PVDC composite rigid sheet, comprising the following steps: (1) Preparation of terminal amino macromolecular ultraviolet absorbers: S1: Cyanurium chloride and acetone are mixed and stirred evenly at 5°C. A solution of 4-fluoro-4'-hydroxybenzophenone and an aqueous solution of NaOH are added, and the mixture is reacted in an ice-water bath. After the reaction, the mixture is filtered and washed to obtain the UV-resistant derivative. S2: Tetrahydrofuran, the UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine are mixed and heated to obtain the aldehyde-terminated UV-resistant derivative. S3: Anhydrous ethanol, the aldehyde-terminated UV-resistant derivative, 1,10-diaminodecane, and glacial acetic acid are mixed evenly and heated under a nitrogen atmosphere. After the reaction, the mixture is filtered, washed, and dried to obtain the amine-terminated macromolecular UV absorber. In S1, the ratio of cyanurium chloride, acetone, 4-fluoro-4'-hydroxybenzophenone solution, and NaOH aqueous solution is 1 g: 7 mL. 6 mL: 50 mL; the 4-fluoro-4'-hydroxybenzophenone solution was obtained by mixing 4-fluoro-4'-hydroxybenzophenone and acetone at a ratio of 1 g: 8 mL; the concentration of the NaOH aqueous solution was 0.2 mol / L; in S1, the process conditions for the ice-water bath reaction were: temperature 0℃, time 4 h; in S2, the mass ratio of tetrahydrofuran, anti-UV derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine was 100:10:10:5; in S2, the process conditions for the heating reaction were: temperature 60℃, time 1 h; in S3, the mass ratio of anhydrous ethanol, terminal aldehyde anti-UV derivative, 1,10-diaminodecane, and glacial acetic acid was 100:10:12:0.5; in S3, the process conditions for the heating reaction were: temperature 80℃, time 12 h; (2) Preparation of quaternized epoxidized soybean oil: Step 1.1: N,N-dimethyl-11-aminoundecanoic acid and triphenylphosphine are mixed evenly, then epoxidized soybean oil is added. The mixture is heated under a nitrogen atmosphere to obtain tertiary amination epoxidized soybean oil. Step 1.2: N,N-dimethylformamide, tertiary amination epoxidized soybean oil, and 1-chlorododecane are mixed and subjected to microwave reaction followed by vacuum distillation to obtain quaternized epoxidized soybean oil. In Step 1.1, the mass ratio of N,N-dimethyl-11-aminoundecanoic acid, triphenylphosphine, and epoxidized soybean oil is 0. .9:0.01:1.0; In step 1.1, the heating reaction conditions are: temperature 100℃, time 3h; In step 1.2, the mass ratio of N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane is 8:1:0.5; In step 1.2, the microwave reaction conditions are: power 600W, temperature 130℃, time 2h; In step 1.2, the vacuum distillation conditions are: vacuum degree -0.098MPa, temperature 90℃, time 1h; (3) Preparation of PVC substrate: Step 1: Mix epoxy resin and quaternized epoxidized soybean oil evenly, heat to 50℃, add terminal amino macromolecular UV absorber and stir evenly to obtain a mixed slurry; Step 2: Mix PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and the mixed slurry, knead, press, and heat-cur to obtain PVC substrate; In Step 1, the mass ratio of epoxy resin, quaternized epoxidized soybean oil and terminal amino macromolecular UV absorber is 1:1:0.25; In Step 2, the mass ratio of PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry is 10:0.5:1.2:1.5; In Step 2, the kneading process conditions are: temperature 170℃, time 10min; the pressing process conditions are: temperature 160℃, time 3min; the heat-curing process conditions are: temperature 130℃, time 3h; (4) Preparation of PVC / PVDC composite rigid sheets: Take a PVC substrate, coat one side of it with adhesive, dry it to form an adhesive layer, then coat it with PVDC emulsion, dry it to form a PVDC layer, and cure it to obtain a PVC / PVDC composite rigid sheet; the thickness of the PVC substrate is 0.35 mm; the coating amount of adhesive is 1 g / m². 2 The coating amount of PVDC emulsion is 8 g / m². 2 The PVC substrate was subjected to corona treatment before the adhesive was applied. The specific process conditions were: voltage 10KV, distance between the electrode and the PVC substrate 2mm, and pulse frequency 10KHz. The drying process conditions were: temperature 60℃ and time 5min. The curing process conditions were: temperature 25℃ and time 24h.

[0040] Comparative Example 1: Compared with Example 1, the epoxidized soybean oil was not subjected to quaternization treatment, and the other conditions remained the same as in Example 1.

[0041] Comparative Example 2: Compared with Example 1, the terminal amino macromolecular ultraviolet absorber was replaced with ethylenediamine, and the other conditions remained the same as in Example 1.

[0042] Comparative Example 3: Compared with Example 1, the epoxidized soybean oil was not subjected to quaternization treatment, and the terminal amino macromolecular ultraviolet absorber was replaced with ethylenediamine. All other conditions remained the same as in Example 1.

[0043] experiment: Water vapor transmission rate: The water vapor transmission rate of the composite rigid sheet was tested in accordance with GB / T 1037-2021 to characterize its barrier properties. Antibacterial test: The antibacterial rate of the composite hard sheet was tested in accordance with GB / T31402-2023 to characterize its antibacterial properties; Mechanical property testing: The tensile strength of the composite rigid sheet was tested in accordance with GB / T 1040.2-2022 to characterize its mechanical properties. UV aging test: The composite rigid sheet was subjected to UV irradiation according to GB / T 16422.3-2022, and its water vapor transmission rate, antibacterial properties and mechanical properties were tested and recorded.

[0044]

[0045] Based on the data in the table above, the following conclusions can be drawn: Compared with Example 1, Comparative Example 1 did not perform quaternization treatment on epoxidized soybean oil, and the antibacterial rate of the composite hard sheet decreased. This is because epoxidized soybean oil without quaternization does not have antibacterial properties, so the antibacterial rate of the composite hard sheet decreased significantly. Compared with Example 1, Comparative Example 2 replaced the terminal amino macromolecular UV absorber with ethylenediamine. The tensile strength of the composite rigid sheet decreased, and the antibacterial rate, tensile strength and barrier properties after UV irradiation all decreased significantly. This is because ethylenediamine does not have UV-resistant groups and is a small molecule curing agent, which has the risk of migration and precipitation, resulting in a significant decrease in the various properties of the composite rigid sheet. Compared with Example 1, the composite rigid sheet obtained in Comparative Example 3 showed a decrease in all properties. It can be seen that the addition of terminal amino macromolecular ultraviolet absorber and quaternized epoxidized soybean oil in this application can promote the improvement of the overall performance of the composite rigid sheet.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a high-barrier PVC / PVDC composite rigid sheet, characterized in that: Including the following processes: Take a PVC substrate, coat one side of it with an adhesive, dry it to form an adhesive layer, then coat it with a PVDC emulsion, dry it to form a PVDC layer, and cure it to obtain a PVC / PVDC composite rigid sheet. The PVC substrate includes ultraviolet absorbing groups and antibacterial groups.

2. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 1, characterized in that: The PVC substrate is obtained by the following process: Step 1: Mix epoxy resin and quaternized epoxidized soybean oil evenly, heat to 50~60℃, add terminal amino macromolecular ultraviolet absorber and stir evenly to obtain mixed slurry; Step 2: Mix PVC granules, calcium-zinc stabilizer, chloroacetic acid resin and mixed slurry, then knead, press into sheets and heat-cur to obtain PVC substrate.

3. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 2, characterized in that: The preparation process of the terminal amino macromolecular ultraviolet absorber is as follows: S1: Mix cyanuric chloride and acetone, stir evenly at 0~5℃, add 4-fluoro-4'-hydroxybenzophenone solution and NaOH aqueous solution, react in an ice-water bath, filter and wash after the reaction to obtain the anti-ultraviolet derivative; S2: Tetrahydrofuran, UV-resistant derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine are mixed and heated to react, yielding an aldehyde-terminated UV-resistant derivative. S3: Anhydrous ethanol, terminal aldehyde UV absorber derivative, 1,10-diaminodecane, and glacial acetic acid are mixed evenly and heated under a nitrogen atmosphere. After the reaction is completed, the mixture is filtered, washed, and dried to obtain a terminal amino macromolecular UV absorber.

4. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 2, characterized in that: The quaternized epoxidized soybean oil is obtained by the following process: Step 1.1: Mix N,N-dimethyl-11-aminoundecanoic acid and triphenylphosphine evenly, then add epoxidized soybean oil, and heat the mixture under a nitrogen atmosphere to obtain tertiary amination epoxidized soybean oil; Step 1.2: N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane are mixed, microwave reaction is carried out, and vacuum distillation is performed to obtain quaternized ammonium epoxidized soybean oil.

5. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 3, characterized in that: In S1, the ratio of cyanuric chloride, acetone, 4-fluoro-4'-hydroxybenzophenone solution and NaOH aqueous solution is 1g: (7~10)mL: (6~8)mL: 50mL.

6. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 3, characterized in that: In S2, the mass ratio of tetrahydrofuran, anti-UV derivative, 1H-benzimidazole-5-carboxaldehyde, and N,N-diisopropylethylamine is 100:10:(10~16):(5~7).

7. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 3, characterized in that: In S3, the mass ratio of anhydrous ethanol, terminal aldehyde UV-resistant derivative, 1,10-diaminodecane, and glacial acetic acid is 100:10:(12~16):(0.5~1.0).

8. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 4, characterized in that: In step 1.1, the mass ratio of N,N-dimethyl-11-aminoundecanoic acid, triphenylphosphine, and epoxidized soybean oil is (0.9~1.2):(0.01~0.05):(1.0~1.2).

9. The method for preparing a high-barrier PVC / PVDC composite rigid sheet according to claim 4, characterized in that: In step 1.2, the mass ratio of N,N-dimethylformamide, tertiary amination epoxidized soybean oil and 1-chlorododecane is 8:1:(0.5~1.0).

10. A high-barrier PVC / PVDC composite rigid sheet, characterized in that: The preparation method according to any one of claims 1 to 9 is used.

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