Long-chain nylon resin having high gas barrier property and method for producing the same

Abstract

The application provides a high gas barrier nylon 12, a preparation method thereof and an article containing the high gas barrier nylon 12. The high gas barrier nylon 12 comprises a block copolymer of nylon 12 segments and nylon 101 segments, wherein the mass ratio of the total mass of decanediamine and isophthalic acid to the mass of dodecanolactam used in the preparation process is 1:1-3. The long-chain barrier nylon is prepared by introducing the nylon 101 segments containing benzene rings into the main chain of the nylon 12. Compared with a random copolymer of the nylon 12 and the nylon 101, the molecular chain of the long-chain barrier nylon can still maintain higher regularity, and the crystallinity is higher; therefore, the long-chain barrier nylon is easier to be processed and molded while having better barrier performance.

Description

Technical Field

[0001] This invention relates to the field of nylon, and more specifically to long-chain nylon resins with high gas barrier properties for thin film processing and methods for preparing the same. Background Technology

[0002] Nylon 12 possesses excellent toughness and flexibility, low water absorption, good dimensional stability, and is easy to process and mold. Due to its low water absorption, nylon 12 films exhibit low water vapor permeability. However, because of the long carbon chains, low amide bond density, and relatively low molecular chain rigidity in nylon 12, gases easily diffuse through the intermolecular and intramolecular gaps within the film, resulting in relatively high oxygen permeability and poor gas barrier properties. This limits the application of nylon 12 in food packaging films and other similar products. Summary of the Invention

[0003] This invention prepares long-chain nylon with good gas barrier properties by introducing nylon 10I segments into the nylon 12 molecular chain. First, prepolymers of nylon 12 and nylon 10I are prepared separately. Then, the two prepolymers undergo post-condensation polymerization. Through optimization of the polymerization process, a long-chain nylon with higher segment regularity is obtained. This nylon exhibits good gas barrier properties and low-temperature toughness, while also showing good processability, thus achieving the objective of this invention.

[0004] According to a first aspect of the invention, a high gas barrier nylon 12 is provided, comprising a block copolymer of nylon 12 segments and nylon 10I segments, wherein the mass ratio of the total mass of decanediamine and isophthalic acid used in the preparation process to the mass ratio of dodecyl lactam is 1:1 to 3, preferably 1:1.5 to 2.5, and more preferably 1:2.

[0005] Preferably, the relative solution viscosity of the high gas barrier nylon 12 is 1.9 to 2.0, as tested in a 0.5 g / dL m-cresol solution according to ISO 1628-1:1998.

[0006] Preferably, by using a rapid scanning calorimeter, the long-chain nylon resin is first heated to 220°C at a rate of 10K / min, and then rapidly cooled to 20°C at a rate of 30K / min. The heat of crystallization of the high gas barrier nylon 12 during the cooling process is measured to be 55-75 J / g, preferably 71-75 J / g.

[0007] Preferably, the low-temperature notched impact strength of the high gas barrier nylon 12, tested at -30°C according to ISO 179-1:2022, is 6 kJ / m. 2 The above, more preferably 6.1 kJ / m 2 above.

[0008] Preferably, the 100µm cast film of the copolymer resin was tested using an oxygen permeability tester according to ISO 15105-2, and the helium permeability of the high gas barrier nylon 12 was 1200cm. 3 / (m 2 • 24h • 0.1MPa or less, more preferably 1000cm 3 / (m 2 Below 0.1 MPa (24h).

[0009] According to a second aspect of the present invention, a method for preparing nylon 12 with high gas barrier properties is provided, comprising the following steps:

[0010] (1) In a stirred container A, dodecyl lactam, diacid end-capping agent and water are added. After being kept at 240-280℃ for 3-5 hours, the reaction pressure is maintained at 2.5-4MPa. Then the reaction system is depressurized to atmospheric pressure and reacted at -30-90kPa to obtain the prepolymer of nylon 12.

[0011] (2) In a stirring container B, add decanediamine, isophthalic acid, diamine end-capping agent and water. After standing at 240-280℃ for 3-5 hours, maintain the reaction pressure at 2.5-4MPa. Then, after depressurizing the reaction system to atmospheric pressure, react at -30-90kPa to obtain the prepolymer of nylon 10I.

[0012] (3) After transferring the nylon 12 prepolymer obtained in step (1) to the stirring container C, the nylon 10I prepolymer obtained in step (2) is added under stirring, and the reaction is carried out under negative pressure; then the product is discharged, water-cooled, and pelletized to obtain long-chain nylon resin.

[0013] The mass ratio of the total mass of decanediamine and isophthalic acid to the mass of dodecyl lactam is 1:1 to 3, preferably 1:1.5 to 2.5, and more preferably 1:2.

[0014] Preferably, in step (1), the reaction is carried out under conditions of -30 to 90 kPa for 0.5 to 1 h.

[0015] Preferably, in step (2), the reaction is carried out under conditions of -30 to 90 kPa for 0.5 to 1 h.

[0016] Preferably, in step (3), the temperature of the reaction system is 200-220℃, more preferably 200-210℃; the reaction pressure is 10-30kPa; and the reaction time is 30-60min, more preferably 30-50min.

[0017] Preferably, the dicarboxylic acid end-capping agent is one or more selected from oxalic acid, adipic acid, sebacic acid, terephthalic acid and isophthalic acid, more preferably adipic acid.

[0018] Preferably, the diamine end-capping agent is one or more selected from ethylenediamine, hexamethylenediamine, p-phenylenediamine and m-phenylenediamine, more preferably hexamethylenediamine.

[0019] Preferably, the amount of the dicarboxylic acid capping agent is 0.5% to 3% relative to the total mass of dodecanoic acid in step (1), more preferably 1% to 1.5%.

[0020] Preferably, the amount of the diamine capping agent is 0.5% to 3% relative to the total mass of decanediamine and m-benzoic acid in step (2), more preferably 1.5% to 2.5%.

[0021] Preferably, the amount of water used in step (1) is 5% to 15% relative to the total mass of dodecanoic acid in step (1), more preferably 10%.

[0022] Preferably, the amount of water used in step (2) is 5% to 15% relative to the total mass of decanediamine and m-benzoic acid in step (2), more preferably 10%.

[0023] Preferably, the molar ratio of the diacid end-capping agent to the diamine end-capping agent is (1.03-1.07):1, more preferably 1.05:1.

[0024] Preferably, the relative solution viscosity of the high gas barrier nylon 12 of the present invention is 1.9 to 2.0, as tested in a 0.5 g / dL m-cresol solution according to ISO 1628-1:1998.

[0025] Preferably, by using a rapid scanning calorimeter, the long-chain nylon resin is first heated to 220°C at a rate of 10K / min, and then rapidly cooled to 20°C at a rate of 30K / min. The heat of crystallization of the high gas barrier nylon 12 of the present invention during the cooling process is measured to be 55-75 J / g, preferably 60-75 J / g.

[0026] According to a third aspect of the invention, an article is provided comprising nylon 12 with high gas barrier properties as described in the invention.

[0027] The greater the heat release of long-chain resins, the higher the regularity of their chain segments.

[0028] The technical solution provided by this invention has the following beneficial effects:

[0029] (1) In this invention, a long-chain barrier nylon is prepared by introducing a nylon 10I segment containing a benzene ring onto the main chain of nylon 12. Compared with the random copolymer of nylon 12 and nylon 10I, its molecular chain can still maintain a high degree of regularity and higher crystallinity. While having good barrier properties, it is easier to process and mold.

[0030] (2) In this invention, the polymerization of nylon resin is divided into four steps. Step 1 and Step 2 respectively obtain carboxyl-terminated nylon 12 prepolymer and amino-terminated nylon 10I prepolymer. In Step 2, after the nylon 12 prepolymer and nylon 10I prepolymer are fully mixed, the degree of amide exchange reaction in the reaction system is suppressed by controlling the reaction temperature and the vapor pressure of the reaction, thereby obtaining a long-chain nylon resin with higher chain segment regularity. Detailed Implementation

[0031] To better understand the technical solution of the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0032] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0033] Dodecyl lactam was purchased from Wanhua Chemical, adipic acid and hexamethylenediamine were purchased from Henan Shenma, and isophthalic acid, trimalonic acid and isophthalic acid were purchased from Aldrich.

[0034] The relative viscosity was determined according to ISO 1628-1:1998 in a 0.5 g / dL m-cresol solution.

[0035] The crystallization rate and melting endothermic properties of nylon 12 resin were tested using a rapid scanning calorimeter. The long-chain nylon resin was first heated to 220°C at a rate of 10 K / min, and then rapidly cooled to 20°C at a rate of 30 K / min. The higher the exothermic heat of crystallization and the higher the melting peak during the cooling process, the higher the chain segment regularity of the nylon resin.

[0036] The low-temperature notched impact strength was obtained by testing at -30°C according to ISO 179-1:2022.

[0037] The helium permeability was obtained by testing the 100µm cast film of the copolymer resin using an oxygen permeability tester according to ISO 15105-2.

[0038] Comparative Example 1

[0039] In a 1m 3 In a stirring container, 200 kg of dodecyl lactam, 30 kg of water, 3 kg of adipic acid, 50.91 kg of decanediamine, and 49.09 kg of isophthalic acid were added. The mixture was then heated to 260°C and held for 3 hours. The pressure was maintained at 3.3 MPa. Subsequently, the reaction system was depressurized to atmospheric pressure and held at 240°C under a vacuum of -60 kPa for 60 minutes. The mixture was then discharged at 240°C, water-cooled, and pelletized to obtain nylon resin.

[0040] Comparative Example 2

[0041] 1) In a 0.5m 3 In a stirred container, 200 kg of dodecyl lactam, 20 kg of water, and 2 kg of adipic acid were added. The mixture was heated to 260°C and held for 3 hours while maintaining a pressure of 3.5 MPa. The system was then depressurized to atmospheric pressure and evacuated to -60 kPa at 240°C. After the reaction system was held for 0.5 hours, nylon 12 prepolymer was obtained.

[0042] 2) In a 0.5m 3 In a stirred container, 50.91 kg of decanediamine, 49.09 kg of isophthalic acid, 10 kg of water, and 1.515 kg of hexamethylenediamine were added. The mixture was heated to 260°C and held for 3 hours, maintaining a pressure of 2.7 MPa. The system was then depressurized to atmospheric pressure and evacuated to -60 kPa at 240°C. After the reaction system was held for 0.5 hours, the prepolymer of Nylon 10I was obtained.

[0043] 3) Transfer the nylon 12 prepolymer obtained in step (1) to a 1m 3 After stirring the container, add the nylon 10I prepolymer obtained in step (2) under stirring. Control the temperature of the reaction system at 240℃, evacuate to -60kPa and react for 30 minutes. After the reaction system returns to normal pressure, discharge the material, cool it with water and granulate it to obtain long-chain nylon resin.

[0044] Example 1

[0045] 1) Following steps (1) and (2) of Comparative Example 2, prepolymers of Nylon 12 and Nylon 10I were obtained;

[0046] 2) The obtained nylon 12 prepolymer was transferred to a 1m... 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 200℃ and react for 30 minutes under 10kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0047] Example 2

[0048] 1) Following steps (1) and (2) of Comparative Example 2, prepolymers of Nylon 12 and Nylon 10I were obtained;

[0049] 2) The obtained nylon 12 prepolymer was transferred to a 1m... 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 200℃ and react for 45 minutes under 10kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0050] Example 3

[0051] 1) Following steps (1) and (2) of Comparative Example 2, prepolymers of Nylon 12 and Nylon 10I were obtained;

[0052] 2) The obtained nylon 12 prepolymer was transferred to a 1m... 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 210℃ and react for 45 minutes under 10kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0053] Example 4

[0054] 1) Following steps (1) and (2) of Comparative Example 2, prepolymers of Nylon 12 and Nylon 10I were obtained;

[0055] 2) The obtained nylon 12 prepolymer was transferred to a 1m... 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 210℃ and react for 45 minutes under 20kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0056] Example 5

[0057] 1) Following steps (1) and (2) of Comparative Example 2, prepolymers of Nylon 12 and Nylon 10I were obtained;

[0058] 2) The obtained nylon 12 prepolymer was transferred to a 1m... 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 210℃ and react for 45 minutes under 30kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0059] Example 6

[0060] 1) In a 0.5m 3 In a stirred container, 300 kg of dodecyl lactam, 30 kg of water, and 3 kg of adipic acid were added. The mixture was heated to 260°C and held for 3 hours while maintaining a pressure of 4 MPa. The system was then depressurized to atmospheric pressure and evacuated to -60 kPa at 240°C. After the reaction system was held for 0.5 hours, a prepolymer of nylon 12 was obtained.

[0061] 2) In a 0.5m 3 In a stirred container, 50.91 kg of decanediamine, 49.09 kg of isophthalic acid, 10 kg of water, and 2.272 kg of hexamethylenediamine were added. The mixture was heated to 260°C and held for 3 hours, maintaining a pressure of 2.5 MPa. The system was then depressurized to atmospheric pressure and evacuated to -60 kPa at 240°C. After the reaction system was held for 0.5 hours, the prepolymer of Nylon 10I was obtained.

[0062] 3) Transfer the nylon 12 prepolymer obtained in step (1) to a 1m 3 After stirring the container, add the nylon 10I prepolymer obtained in step (2) under stirring. Control the temperature of the reaction system at 210℃ and react for 45 minutes under 20kPa vapor pressure. Then, discharge the material, cool it with water, and cut it into pellets to obtain long-chain nylon resin.

[0063] Example 7

[0064] 1) Following step (1) of Comparative Example 2, a prepolymer of nylon 12 was obtained;

[0065] 2) In a 0.5m 3 In a stirred container, 101.83 kg of decanediamine, 98.17 kg of isophthalic acid, 10 kg of water, and 1.515 kg of hexamethylenediamine were added. The mixture was heated to 260°C and held for 3 hours, maintaining a pressure of 3 MPa. The system was then depressurized to atmospheric pressure and evacuated to -60 kPa at 240°C. After the reaction system was held for 0.5 hours, the prepolymer of Nylon 10I was obtained.

[0066] 3) Transfer the obtained nylon 12 prepolymer to a 1m 3 After stirring the container, add the prepolymer of Nylon 10I while stirring. Control the temperature of the reaction system at 210℃ and react for 45 minutes under 30kPa vapor pressure. Then, discharge the material, cool it with water, and granulate it to obtain long-chain nylon resin.

[0067] The long-chain nylon resins obtained in Comparative Examples 1-2 and Examples 1-7 were tested for their relative viscosity, low-temperature notched impact strength, helium permeability, and heat release during the cooling process in their DSC tests.

[0068] Table 1: Test results of long-chain nylon resins in Comparative Examples 1-2 and Examples 1-7

[0069]

[0070] Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A high gas barrier nylon 12, comprising a block copolymer of nylon 12 segments and nylon 10I segments, wherein, The total mass ratio of decanediamine and isophthalic acid used in the preparation process to dodecyl lactam is 1:1~3; Using a rapid scanning calorimeter, the long-chain nylon resin was first heated to 220°C at a rate of 10 K / min, and then rapidly cooled to 20°C at a rate of 30 K / min. The heat of crystallization of the high gas barrier nylon 12 during the cooling process was measured to be 55~75 J / g.

2. The high gas barrier nylon 12 according to claim 1, wherein, According to ISO 1628-1:1998, the relative solution viscosity of the high gas barrier nylon 12 in a 0.5 g / dL m-cresol solution is 1.9~2.0; and / or The total mass ratio of decanediamine and isophthalic acid used in the preparation process to dodecyl lactam is 1:1.5~2.

5.

3. The nylon 12 with high gas barrier properties according to claim 1, wherein, The total mass ratio of decanediamine and isophthalic acid used in the preparation process to dodecyl lactam is 1:

2.

4. The high gas barrier nylon 12 according to claim 1 or 2, wherein, Using a rapid scanning calorimeter, the long-chain nylon resin was first heated to 220°C at a rate of 10 K / min, and then rapidly cooled to 20°C at a rate of 30 K / min. The heat of crystallization of the high gas barrier nylon 12 during the cooling process was measured to be 71~75 J / g.

5. The high gas barrier nylon 12 according to claim 1 or 2, wherein, According to ISO 179-1:2022, the low-temperature notched impact strength of the high gas barrier nylon 12, tested at -30°C, is 6 kJ / m. 2 above.

6. The high gas barrier nylon 12 according to claim 5, wherein, According to ISO 179-1:2022, the low-temperature notched impact strength of the high gas barrier nylon 12, tested at -30°C, is 6.1 kJ / m. 2 above.

7. The high gas barrier nylon 12 according to claim 1 or 2, wherein, Using an oxygen permeability tester according to ISO 15105-2, the helium permeability of the 100µm cast film of the copolymer resin was tested, and the high gas barrier nylon 12 had a helium permeability of 1200cm. 3 / (m 2 Below 0.1 MPa (24h).

8. The high gas barrier nylon 12 according to claim 7, wherein, The 100µm cast film of the copolymer resin was tested using an oxygen permeability tester according to ISO 15105-2. The helium permeability of the high gas barrier nylon 12 was 1000cm. 3 / (m 2 Below 0.1 MPa (24h).

9. A method for preparing nylon 12 with high gas barrier properties, comprising the following steps: (1) Add dodecyl lactam, diacid end-capping agent and water to a stirring container A, and keep it at 240~280℃ for 3~5h. Then maintain the reaction pressure at 2.5~4MPa. After the reaction system is depressurized to atmospheric pressure, react at -30~90kPa to obtain the prepolymer of nylon 12. (2) In a stirring container B, add decanediamine, isophthalic acid, diamine end-capping agent and water. After standing at 240~280℃ for 3~5h, maintain the reaction pressure at 2.5~4MPa. Then, after depressurizing the reaction system to atmospheric pressure, react at -30~90kPa to obtain the prepolymer of nylon 10I. (3) After transferring the nylon 12 prepolymer obtained in step (1) to the stirring container C, add the nylon 10I prepolymer obtained in step (2) under stirring, and react under negative pressure. Then, discharge the product, cool it with water, and granulate it to obtain long-chain nylon resin. The reaction system temperature is 200~220℃; the reaction pressure is 10~30kPa; and the reaction time is 30~60min. The total mass ratio of decanediamine and isophthalic acid to dodecyl lactam is 1:1~3.

10. The method for preparing nylon 12 with high gas barrier properties according to claim 9, wherein, In step (1), the reaction is carried out under conditions of -30~90kPa for 0.5~1h; And / or, in step (2), the reaction is carried out under conditions of -30~90kPa for 0.5~1h; And / or, in step (3), the reaction system temperature is 200~210℃; the reaction pressure is 10~30kPa; and the reaction time is 30~50min. And / or, the total mass ratio of decanediamine and isophthalic acid to dodecyl lactam is 1:1.5~2.

5.

11. The method for preparing nylon 12 with high gas barrier properties according to claim 9, wherein, The total mass ratio of decanediamine and isophthalic acid to dodecyl lactam is 1:

2.

12. The method for preparing nylon 12 with high gas barrier properties according to claim 9 or 10, wherein, The dicarboxylic acid capping agent is selected from one or more of oxalic acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid; And / or, the diamine end-capping agent is one or more selected from ethylenediamine, hexamethylenediamine, p-phenylenediamine and m-phenylenediamine; And / or, relative to the total mass of dodecanoic acid in step (1), the amount of the dicarboxylic acid capping agent is 0.5% to 3%; And / or, relative to the total mass of decanediamine and m-benzoic acid in step (2), the amount of the diamine capping agent is 0.5% to 3%.

13. The method for preparing nylon 12 with high gas barrier properties according to claim 12, wherein, The dicarboxylic acid end-capping agent is oxalic acid; And / or, the diamine end-capping agent is selected from ethylenediamine; And / or, relative to the total mass of dodecanoic acid in step (1), the amount of the dicarboxylic acid capping agent is 1% to 1.5%; And / or, relative to the total mass of decanediamine and m-benzoic acid in step (2), the amount of the diamine capping agent is 1.5% to 2.5%.

14. The method for preparing nylon 12 with high gas barrier properties according to claim 9 or 10, wherein, The amount of water used in step (1) is 5% to 15% relative to the total mass of dodecanoic acid in step (1); And / or, relative to the total mass of decanediamine and m-benzoic acid in step (2), the amount of water used in step (2) is 5% to 15%; And / or, the molar ratio of the dicarboxylic acid end-capping agent to the diamine end-capping agent is (1.03-1.07):

1.

15. The method for preparing nylon 12 with high gas barrier properties according to claim 14, wherein, The amount of water used in step (1) is 10% relative to the total mass of dodecanoic acid in step (1); And / or, the amount of water used in step (2) is 10% relative to the total mass of decanediamine and m-benzoic acid in step (2); And / or, the molar ratio of the diacid end-capping agent to the diamine end-capping agent is 1.05:

1.

16. An article comprising nylon 12 with high gas barrier properties according to any one of claims 1 to 8.

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