FLAME-RETARDANT SEMI-AROMATIC POLYAMIDE AND PREPARATION METHOD THEREOF

Abstract

The invention discloses a flame-retardant semi-aromatic polyamide derived from the following monomers: a diacid monomer A: where A1 is terephthalic acid or terephthalic acid and other diacid, terephthalic acid accounts for 50 to 100 mol % of A1, and A2 is [(6-oxido-6H-dibenzo-(c,e)(1,2)-oxaphosphorin-6-ketone)-methyl]-butanedioic acid, A1+A2=100 mol %, A1=90 to 99 mol %, A2=1 to 10 mol %; and diamine monomer B: one or more of diamine monomers containing 4 to 36 carbon atoms. In the present invention, by an in situ polymerization, a specific flame-retardant monomer [(6-oxido-6H-dibenzo-(c,e)(1,2)-oxaphosphorin-6-ketone)-methyl]-butanedioic acid is copolymerized in a semi-aromatic polyamide chain segment, excellent mechanical properties and low water absorption can be obtained.

Claims

1. A flame-retardant semi-aromatic polyamide, wherein the flame-retardant semi-aromatic polyamide is derived from the following monomers: a diacid monomer A including a diacid monomer A1 and a diacid monomer A2, wherein the diacid monomer A1 is terephthalic acid or terephthalic acid and other diacid, terephthalic acid accounts for 50 to 100 mol % of the diacid monomer A1, and the diacid monomer A2 is [(6-oxido-6H-dibenzo-(c,e)(1,2)-oxaphosphorin-6-ketone)-methyl]-butanedioic acid, a total content of the diacid monomer A1 and the diacid monomer A2 is 100 mol %, a content of the diacid monomer A1 is 90 to 99 mol %, and a content of the diacid monomer A2 is 1 to 10 mol %; and a diamine monomer B including one or more of diamine monomers containing 4 to 36 carbon atoms.

2. The flame-retardant semi-aromatic polyamide according to claim 1, wherein in the diacid monomer A, the content of the diacid monomer A2 is 2.5 to 7.7 mol %.

3. The flame-retardant semi-aromatic polyamide according to claim 1, wherein the other diacid is selected from at least one of an aliphatic diacid and an aromatic diacid.

4. The flame-retardant semi-aromatic polyamide according to claim 3, wherein the aliphatic diacid is selected from one or more of oxalic acid, malonic acid, 1,4-succinic acid, 1,5-glutaric acid, 1,6-adipic acid, 1,7-pimelic acid, 1,8-suberic acid, 2-methyl suberic acid, 1,9-azelaic acid, 1,10-sebacic acid, 1,11-undecanedioic acid, 1,12-dodecanedioic acid, 1,13-tridecanedioic acid, 1,14-tetradecanedioic acid, and cyclohexanedicarboxylic acid.

5. The flame-retardant semi-aromatic polyamide according to claim 3, wherein the aromatic diacid is selected from at least one of isophthalic acid and naphthalenedicarboxylic acid.

6. The flame-retardant semi-aromatic polyamide according to claim 1, wherein the diamine monomer B is selected from one or more of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecandiamine, 1,18-octadecanediamine, 1-butyl-1,2-ethylenediamine, 1,1-dimethyl-1,4-butanediamine, 1-ethyl-1,4-butanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptanediamine, 2,3-dimethyl-1,7-heptanediamine, 2,4-dimethyl-1,7-heptanediamine, 2,5-dimethyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine, 1,3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine.

7. The flame-retardant semi-aromatic polyamide according to claim 6, wherein the diamine monomer B is selected from at least one of 1,10-decanediamine and 1,6-hexanediamine.

8. The flame-retardant semi-aromatic polyamide according to claim 3, wherein the other diacid is selected from at least one of isophthalic acid and 1,6-adipic acid.

9. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 1, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

10. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 2, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

11. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 3, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

12. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 4, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

13. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 5, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

14. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 6, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

15. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 7, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

16. A preparation method of the flame-retardant semi-aromatic polyamide according to claim 8, comprising the following steps: weighing the diacid monomer A, the diamine monomer B, a catalyst, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating; putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the flame-retardant semi-aromatic polyamide.

Description

DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention is further illustrated by the following embodiments, but which shall not be understood as limitation of the protection scope of the present invention.

[0027] Raw materials used in the present invention are derived from commercially available products. [0028] BCPPO: bis(4-carboxyphenyl)phenyl phosphine oxide; [0029] CEPPA: 3-hydroxyphenylphosphinyl propanoic acid [0030] CEMPO: bis(2-carboxyethyl)methyl phosphine oxide; and [0031] MCA: cyanuric acid.

[0032] A preparation method of a polyamide in Embodiments and Comparative Examples: according to a ratio of each component in Tables 1 to 4, weighing a diacid monomer A, a diamine monomer B, sodium hypophosphite, and deionized water into a high-temperature high-pressure reactor, after gas aerating and exchange to make atmosphere in the reactor as nitrogen, heating up to 160 to 180° C., reacting at a constant temperature for 0.5 hours, continuing to heat up to 200 to 210° C., and reacting at a constant temperature for 0.5 hours, continuing to heat up to 240 to 250° C., reacting at a constant temperature for 1 hour, draining for about 0.5 hours, discharging, and granulating, putting the granulated material into a rotating drum, evacuating to make a pressure lower than 3000 Pa, heating up to 230 to 260° C., reacting for 3 hours, stopping heating, and after the temperature returning to room temperature, discharging the material to obtain the semi-aromatic polyamide.

[0033] Test Methods of Various Properties

[0034] (1) End groups: a potentiometric titrator was used to determine an amino end group content and a carboxyl end group content of the polymer. A sample of 0.45 g polyamide was weighed, 50 mL of preheated and dissolved o-cresol was added and heated to reflux until the sample was dissolved. After cooling to 50° C. in a water tank at 50° C., 0.5 mL of formaldehyde solution was added, a magnetic stirrer was put in to stir the solution, an electrode test section of the automatic potentiometric titrator was immersed into the solution, and carboxyl end group data were measured by titration with a calibrated KOH-ethanol solution. 0.45 g of the sample was weighed, 45 mL of phenol and 3 mL of anhydrous methanol were added, heated to reflux until the sample was dissolved. After cooling to 50° C. in the water tank at 50° C., the magnetic stirrer was put in to stir the solution, the electrode test section of the automatic potentiometric titrator was immersed into the solution, and amino end group data were measured by titration with a calibrated hydrochloric acid solution.

[0035] (2) Relative viscosity: with reference to a standard GB/T 12006.1-1989, a Ubbelohde viscometer was used to measure a relative viscosity of a product with a concentration of 0.25 g/dL in 98% concentrated sulfuric acid at (25±0.01°) C.

[0036] In the present invention, a molecular weight of the polyamide is determined according to an end group content and a relative viscosity of the polyamide. Under the premise of the same monomer, if the relative viscosity and the end group content are similar, the molecular weight of the polyimide is similar.

[0037] (3) Tensile strength: with reference to ISO 527, tensile strength of a resin material was tested.

[0038] (4) Bending strength: with reference to a standard ISO 178, bending strength of a resin material was tested.

[0039] (5) Notched impact strength/unnotched impact strength: with reference to a standard ISO 180, impact strength of a resin material was tested.

[0040] (6) UL94 flame-retardant rating: measured with reference to GB/T2408-1996, with a test sample size of 13 cm×1.3 cm×0.3 cm.

[0041] (7) Limiting oxygen index (LOI): measured with reference to a standard GB/T5454-1997, with a test sample size of 12 cmxl cm×0.4 cm.

[0042] (8) Water absorption: with reference to a standard ISO 62:2008, water absorption of a resin material was tested.

TABLE-US-00001 TABLE 1 Ratio of each component of the polyamide and test results in Embodiments 1 to 4 Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 10T10DDP 10T10DDP 10T10DDP 10T10DDP mol % of DDP accounting 1 2.5 5 7.7 for a diacid monomer mol % of terephthalic acid 99 97.5 95 92.3 and/or other diacid monomer Amino end group mol/t 72 74 77 75 Carboxyl end group mol/t 108 138 133 136 Relative viscosity 1.88 1.87 1.87 1.87 Tensile strength MPa 73.2 76.0 75.2 76.8 Bending strength MPa 92.5 95.3 94.2 95.7 Notched impact strength kJ/m.sup.2 5 6 6 6 Unnotched impact strength kJ/m.sup.2 35 39 39 38 UL flame-retardant rating V0 V0 V0 V0 LOI 32 35 35 35 Water absorption % 0.6 0.3 0.3 0.3

TABLE-US-00002 TABLE 2 Ratio of each component of the polyamide and test results in Embodiments 5 to 8 Embodiment 5 Embodiment 6 Embodiment 7 Embodiment 8 10T10DDP 6T/66/6DDP 6T/66/6DDP 6T/6I/6DDP mol % of DDP accounting 10 1 10 1 for a diacid monomer mol % of terephthalic acid 90 99 (T:6 = 90 (T:6 = 99 (T:I = and/or other diacid monomer 50:50) 50:50) 80:20) Amino end group mol/t 71 76 89 70 Carboxyl end group mol/t 130 132 140 110 Relative viscosity 1.86 1.87 1.85 1.88 Tensile strength MPa 74.3 73.1 72.2 76.3 Bending strength MPa 92.7 95.9 93.8 96.8 Notched impact strength kJ/m.sup.2 5 5 6 5 Unnotched impact strength kJ/m.sup.2 35 38 40 36 UL flame-retardant rating V0 V0 V0 V0 LOI 34 31 34 32 Water absorption % 0.6 0.7 0.7 0.6

TABLE-US-00003 TABLE 3 Ratio of each component of the polyamide and test results in Embodiments 9 to 11 Embodiment 9 Embodiment 10 Embodiment 11 6T/6I/6DDP 10T/66/10DDP 10T10I10DDP mol % of DDP accounting 10 5 5 for a diacid monomer mol % of terephthalic acid 90 (T:I = 95 (T:6 = 95 (T:I = and/or other diacid monomer 80:20) 80:20) 80:20) Amino end group mol/t 85 88 81 Carboxyl end group mol/t 135 137 136 Relative viscosity 1.86 1.85 1.86 Tensile strength MPa 74.6 75.0 75.0 Bending strength MPa 94.5 94.8 105 Notched impact strength kJ/m.sup.2 6 6 8 Unnotched impact strength kJ/m.sup.2 39 38 42 UL flame-retardant rating V0 V0 V0 LOI 35 35 35 Water absorption % 0.7 0.6 0.5

TABLE-US-00004 TABLE 4 Ratio of each component of the polyamide and test results in Comparative examples Comparative Comparative Comparative Comparative example 1 example 2 example 3 example 4 10T 10T10I PA66 PA66/6DDP mol % of a flame-retardant monomer 0 0 0 5 accounting for a diacid monomer mol % of terephthalic acid 100 100 (T:I = 100 95 and/or other diacid monomer 80:20) Amino end group mol/t 68 71 69 72 Carboxyl end group mol/t 104 112 100 110 Relative viscosity 1.89 1.88 1.88 1.86 Tensile strength MPa 78.1 78.0 63.7 41 Bending strength MPa 97.9 96.1 80.5 58.5 Notched impact strength kJ/m.sup.2 5 5 5 4 Unnotched impact strength kJ/m.sup.2 37 35 35 30 UL flame-retardant rating — — — V0 LOI 26 26 21 30 Water absorption % 1.2 1.2 3.0 3.5 Comparative Comparative Comparative example 5 example 6 example 7 10T10BCPPO 10T10CEPPA 10T10I10DDP mol % of a flame-retardant monomer 5 5 5 accounting for a diacid monomer mol % of terephthalic acid 95 95 95 (T:I = and/or other diacid monomer 20:80) Amino end group mol/t 73 75 81 Carboxyl end group mol/t 121 119 136 Relative viscosity 1.89 1.89 1.86 Tensile strength MPa 74.6 72.9 63.0 Bending strength MPa 93.7 92.8 47.0 Notched impact strength kJ/m.sup.2 5 6 9 Unnotched impact strength kJ/m.sup.2 33 33 40 UL flame-retardant rating V0 V0 V0 LOI 32 32 30 Water absorption % 1.5 1.6 1.1 Comparative Comparative Comparative example 8 example 9 example 10 10T10DDP 10T10MCA 10T10CEMPO mol % of a flame-retardant monomer 30 5 5 accounting for a diacid monomer mol % of terephthalic acid 70 95 95 and/or other diacid monomer Amino end group mol/t 90 78 75 Carboxyl end group mol/t 143 115 117 Relative viscosity 1.84 1.89 1.89 Tensile strength MPa 62.5 60.7 55.6 Bending strength MPa 83.3 78.2 65.4 Notched impact strength kJ/m.sup.2 6 4 4 Unnotched impact strength kJ/m.sup.2 45 29 27 UL flame-retardant rating V0 V2 V2 LOI 36 25 24 Water absorption % 1.3 1.5 1.9

[0043] It can be seen from Embodiments 1 to 5 that at a preferred DDP content range, a flame retardant effect and mechanical properties are good, and water absorption is low.

[0044] It can be seen from Comparative Example 1 and Table 1 that for an in situ polymerization of DDP into 10T, not only an excellent flame-retardant property is obtained, but also mechanical properties are maintained and even improved and water absorption is reduced.

[0045] It can be seen from Comparative Example 1 or 6 that when the in situ copolymerized flame-retardant monomer is CEPPA, although there are good mechanical properties and flame-retardant rating, water absorption is relatively high.

[0046] It can be seen from Comparative Example 1 or 5 that when the in situ copolymerized flame-retardant monomer is BCPPO, mechanical properties are decreased and water absorption is high.

[0047] It can be seen from Comparative Example 3 or 4 and Table 1 that after an in situ copolymerization of DDP in an aliphatic polyamide PA66 system, mechanical properties are significantly reduced; while after an in situ copolymerization of DDP in a semi-aromatic polyamide, relatively good mechanical properties are maintained, a flame-retardant property and a water absorption property are significantly improved.

[0048] It can be seen from Embodiment 11 and Comparative Example 7 that when a content of terephthalic acid accounting for the diacid monomer A is too low, it not only reduces a flame-retardant property to a certain extent and causes water absorption to rise, and leads to very poor mechanical properties, making it difficult to achieve application values.

[0049] It can be seen from Comparative Example 8 that when a content of DDP accounting for the diacid monomer A is too high, it also causes a decrease in mechanical properties and an increase in water absorption.

[0050] It can be seen from Comparative example 9 or 10 that when the in situ copolymerized flame-retardant monomer is MCA or CEMPO, a flame-retardant effect and mechanical properties are both relatively poor, and water absorption is relatively high.