TW202325778A - High melting temperature polyamide polymer manufacturing method - Google Patents

Abstract

A high melting temperature polyamide polymer manufacturing method is provided. The method includes: (A1000) performing a pre-polymerization to an amide solution in 200~240℃ and 14.8 ~33.1 kg/cm ²G; (A2000) performing vaporization of the product of the pre-polymerization in 160~230℃; and (A3000) performing a polycondensation to the product of the pre-polymerization after the vaporization, wherein the reacting temperature of the polycondensation temperature is higher than the temperature 20℃ lower than the crystallization temperature of the polyamide polymer, wherein the reacting temperature of the polycondensation temperature is lower than the melting temperature of the polyamide polymer.

Description

A kind of manufacture method of high melting point polyamide macromolecule

The present invention relates to a method for producing high melting point polyamide macromolecules.

Polyamide polymer has the characteristics of high strength and high toughness, and is a thermoplastic polymer with good processability. It is often used as engineering plastics, such as electronic parts, automotive parts and industrial parts (such as gears).

In electronic materials, polyamide polymers, such as nylon 66, are often used as connector brackets. However, with the change of assembly technology, the circuit board gradually adopts surface mount (SMT) technology, so that the connector also needs to pass through a 280-degree soldering furnace, so its heat resistance requires more than 280 degrees Celsius. Since the melting point of nylon 66 is only 265 degrees Celsius, it cannot meet the needs of the application side. Therefore, electronic connectors are gradually switching to high melting point polyamide polymers.

High-melting point polyamide polymers use aromatic dibasic acid monomers for copolymerization to increase the melting temperature (Melting Temperature, Tm) of polyamide. Common specifications require that the melting temperature must be greater than 300 degrees Celsius, such as nylon 6T, nylon 46 etc. However, the increase in the melting temperature of the material causes the process temperature to be close to the cracking temperature of the material, so it is necessary to improve the process method.

The process disclosed in U.S. Patent No. 6,130,312 describes the manufacturing process of high melting point polyamide polymers: dissolving dibasic acid and diamine in water to form a saline solution, and then concentrating at a temperature of 150~160°C to make the salt The aqueous solution was adjusted to the required concentration for the reaction. Finally, the concentrated salt solution was polymerized at 250°C. Finally, the water used as a solvent is evaporated, and then the temperature is raised to 360°C by a twin-screw extruder for repolymerization to obtain a high melting point polyamide polymer. In the above method, an extruder is used to solve the problem of high-viscosity transportation of high-melting polyamide polymers. In order to melt the semi-finished product again, the temperature is raised to 360°C. The reaction produces gelation, which easily leads to the deterioration of the quality of the obtained polyamide polymer. Moreover, the space that can be accommodated by the extruder is relatively low, resulting in low production volume, which is not conducive to the reduction of manufacturing costs.

In addition, the patent No. I546320 of semi-aromatic polyamide and its manufacturing method uses solid-phase polymerization at a lower reaction temperature to avoid the risk of polyamide macromolecule cracking. The process description is as follows: dibasic acid and diamine are mixed in an autoclave to form a salt, and then heated at 230° C. for 3 hours. Carry out the formation reaction of low polymer, and break it at the same time. The resulting reactant was heated in a drier at 230°C for 5 hours under normal pressure nitrogen flow to carry out solid-state polymerization to obtain polyamide with a relative viscosity (Relative Viscosity, RV) of 2.29~2.55.

According to the above process, the actual solid polymerization needs 6~10 hours to achieve the target degree of polymerization, and the size of the solid state polymerization equipment needs to be 50 times the volume of the hourly output, which is quite unfavorable for the utilization of plant space. Therefore, the object of the present invention is to develop a high-melting polyamide polymer with high yield and no need for solid-state polymerization equipment and its manufacturing method.

The invention provides a method for producing high-melting polyamide polymers, which requires shorter reaction time and less equipment space.

The manufacturing method of the high melting point polyamide polymer of the present invention comprises the following steps in sequence: (A1000) Prepolymerizing the amide salt solution at a temperature of 200-240°C and a pressure of 14.8-33.1 kg/cm ² G (A2000) evaporating the product of the prepolymerization reaction at a temperature of 160-230° C.; and (A3000) performing polycondensation reaction on the product of the prepolymerization reaction after evaporation in step A2000, wherein the reaction temperature of the polycondensation reaction is higher than that of the polycondensation reaction The crystallization temperature (Crystallization Temperature, Tc) of the amide polymer is lower than the temperature of 20 ℃, and is lower than the melting temperature (Melting Temperature, Tm) of the polyamide polymer.

In the embodiment of the present invention, the reaction time of step A1000 is 1 hour.

In an embodiment of the present invention, the manufacturing method further includes: (A4000) crushing the product of the polycondensation reaction into particles.

In an embodiment of the present invention, wherein step A4000 is carried out in the first reactor, the manufacturing method further includes: (A5000) transporting the polycondensation reaction product broken into particles to the outside of the first reactor.

In an embodiment of the present invention, the amide salt solution comprises a dibasic acid based on 100 moles, a diamine added in an amount of 100-110 moles, an end-capping agent added in an amount of 0.1-3.0 moles, and The amount of catalyst added is 0.1~2 moles.

In an embodiment of the present invention, the dibasic acid is a single aromatic dibasic acid or a mixture of multiple aromatic dibasic acids.

In an embodiment of the present invention, the dibasic acid is a mixture of aromatic dibasic acid and aliphatic dibasic acid, wherein the proportion of aromatic dibasic acid is greater than 45 mol%.

In an embodiment of the present invention, the capping agent is a compound with a single carboxylic acid and no amine group.

In an embodiment of the present invention, the catalyst is selected from phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof.

As shown in FIG. 1 , the schematic flow chart of the embodiment of the present invention, the manufacturing method of the high melting point polyamide polymer of the present invention includes, for example, the following steps in sequence.

In step A1000, prepolymerize the amide salt solution at a temperature of 200-240° C. and a pressure of 14.8-33.1 kg/cm ² G. In one embodiment, the reaction time is 1 hour, but not limited thereto. Further, the amide salt solution comprises 100 moles of dibasic acid, 100-110 moles of diamine, 0.1-3.0 moles of capping agent, and 0.1 ~2 moles of catalyst.

In one embodiment, the dibasic acid is a single aromatic dibasic acid or a mixture of multiple aromatic dibasic acids. In different embodiments, the dibasic acid is a mixture of aromatic dibasic acid and aliphatic dibasic acid, wherein the proportion of aromatic dibasic acid is greater than 45 mol%. More specifically, dibasic acids are characterized by having two carboxylic acids, such as terephthalic acid, isophthalic acid and other aromatic compounds containing benzene rings, accounting for more than 45 mol% of dibasic acid monomers , and the remaining 0~55 mol% can be used as an aliphatic compound with two carboxylic acids to achieve the effect of adjusting the glass transition temperature (Glass Transition Temperature, Tg) or crystallization temperature of the polymer.

Diamines are mainly aliphatic diamines with carbon numbers of 4~12, such as: 1,4-butanediamine, 1,6-hexamethylenediamine, 1,8-octanediamine, 1,9-nonanediamine Amine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1, 5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 5-methyl-1,9 - Aliphatic diamines such as nonanediamine.

The end-capping agent is a compound with a single carboxylic acid and no amine group, such as aromatic compound: benzoic acid, and aliphatic compound acetic acid can be used as the end-capping agent. The catalyst is selected from phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof.

In step A2000, the product of the prepolymerization reaction is evaporated at a temperature of 160-230°C. Further, the temperature is used to evaporate a solvent such as water.

Step A3000, subjecting the product of the prepolymerization reaction evaporated in step A2000 to a polycondensation reaction, wherein the reaction temperature of the polycondensation reaction is at least 20°C lower than the crystallization temperature (Crystallization Temperature, Tc) of the polyamide polymer, and Below the melting temperature (Melting Temperature, Tm) of polyamide polymer. Furthermore, the temperature of the polycondensation reaction is controlled within ±20° C. of the crystallization temperature of the polyamide macromolecule, so that the polyamide macromolecule may be crystallized. The polycondensation reaction temperature is below the melting temperature of the polyamide polymer, which can reduce the occurrence of cracking of the polyamide polymer.

In one embodiment, the manufacturing method further includes step A4000 of crushing the product of the polycondensation reaction into particles. Thereby, the transportation of products can be facilitated. More specifically, step A4000 is carried out in the first reactor, and the manufacturing method further includes step A5000 of transporting the polycondensation reaction product broken into particles to the outside of the first reactor. Wherein, the present invention can be implemented in a batch reactor or in a continuous reactor.

The effect of the present invention is illustrated by examples below.

Embodiment 1-5

Add 90 kg of water, 23.7 kg of adipic acid, 29.2 kg of terephthalic acid, and 42.9 kg of hexamethylenediamine into a 200-liter mixing tank. After starting the stirring, heat up to 85 degrees Celsius and mix for 60 minutes to ensure that the solution is uniform. Finally, 518 grams of benzoic acid as an end-capping agent and 253 grams of sodium hypophosphite as a catalyst were added, and the solution was delivered to a 200-liter high-pressure reactor. After nitrogen replacement, the temperature of the reaction tank was raised to 230 degrees Celsius for 60 minutes of prepolymerization. After completion, the temperature of the reaction tank was lowered to 160 degrees Celsius, and the steam was discharged. After the water is completely discharged, it is pumped into the second-stage polycondensation reactor with a gear pump, and reacted for 100 minutes at 285 degrees Celsius. Finally, the solid granular product is collected, and the relative viscosity (Relative Viscosity, RV) is 2.32. In Examples 2-5, the feed ratios and reaction conditions of adipic acid, terephthalic acid, and hexamethylenediamine were adjusted, as shown in Table 1 below. Among them, the relative viscosities of the finished products of Examples 1 to 5 are all approximately in the range of 2.2 to 2.6, which is convenient for transportation.

Table 1 Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 raw material 6T/66 6T/6I 6T/6I/66 6T/66 6T/66 6T/66 6T/66 6T/66 6T/66 water (kg) 90 90 90 90 90 90 90 90 90 Adipic acid (kg) 23.7 0 7.2 23.7 23.7 23.7 23.7 23.7 23.7 Terephthalic acid (kg) 32.9 38.8 32.8 32.9 32.9 29.2 29.2 29.2 29.2 Isophthalic acid (kg) 0 17.2 13.6 0 0 0 0 0 0 Hexamethylenediamine (kg) 42.9 40 39.1 42.9 42.9 42.9 42.9 42.9 42.9 Prepolymerization temperature (℃) 230 230 230 230 230 230 230 230 230 Evaporation temperature (℃) 160 160 160 160 160 230 160 240 150 Polycondensation temperature(℃) 285 295 275 290 260 340 250 285 - illustrate Tc+5 Tc+5 Tc+5 Tc+10 Tc-17 Tm + 22 Tc-30 Tc+10 - Finished product melting point Tm(℃) 315.7 325 311 315.2 316.3 318.2 313.9 316.4 - Finished product crystallization point Tc(℃) 279.2 291.8 268 278.46 277.54 279.4 279.4 271.6 - Finished RV 2.32 2.12 2.34 2.61 2.21 3.45~4.2 1.86 2.68 too high to measure

Comparative example 1

Add 90 kg of water, 23.7 kg of adipic acid, 29.2 kg of terephthalic acid, and 42.9 kg of hexamethylenediamine into a 200-liter mixing tank. After starting the stirring, heat up to 85 degrees Celsius and mix for 60 minutes to ensure that the solution is uniform. Drop into 518 grams of benzoic acid (capping agent), 253 grams of sodium hypophosphite (catalyst), and replace the solution to a 200-liter high-pressure reactor. After nitrogen replacement, the temperature of the reaction tank was raised to 230 degrees Celsius for 60 minutes of prepolymerization. Thereafter, the temperature of the reaction tank was raised to 340 degrees at a rate of 2 degrees Celsius per minute, and the pressure was released from 23 kg/cm2G to 0.4 kg/cm2 per minute to atmospheric pressure. When the temperature of the reaction tank reaches 270 degrees Celsius, start timing. After reaching 100 minutes, the polymer in the tank is continuously driven into the extruder by the gear pump for granulation. This is a PA6T/66 copolymer. After testing, the RV of the front product is 3.4, and the RV of the rear product is 4.2. It is speculated that the reason is that the difference between the front product and the rear product is 60 minutes during the unloading process, and gelation is likely to occur at 340 degrees. As a result of the test, due to the high reaction temperature, the RV value exceeded 2.6 to a large extent, and the quality was not stable.

Comparative example 2

Add 90 kg of water, 23.7 kg of adipic acid, 29.2 kg of terephthalic acid, and 42.9 kg of hexamethylenediamine into a 200-liter mixing tank. After starting the stirring, heat up to 85 degrees Celsius and mix for 60 minutes to ensure that the solution is uniform Afterwards, drop into 518 grams of benzoic acid (blocking agent), 253 grams of sodium hypophosphite (catalyst) again, and the solution is delivered to 200 liters of high-pressure reactors. After nitrogen replacement, the temperature of the reaction tank was raised to 230 degrees Celsius for 60 minutes of prepolymerization. After completion, the temperature of the reaction tank was lowered to 160 degrees Celsius, and the steam was discharged. After the water is completely discharged, it is pumped into the second-stage polycondensation reactor with a gear pump, reacted at 250 degrees Celsius for 100 minutes, and finally collects solid granular products, and the RV test is 1.86. Test result, because reaction temperature is too low, can't reach required RV value.

Comparative example 3

Add 90 kg of water, 23.7 kg of adipic acid, 29.2 kg of terephthalic acid, and 42.9 kg of hexamethylenediamine into a 200-liter mixing tank. After starting the stirring, heat up to 85 degrees Celsius and mix for 60 minutes to ensure that the solution is uniform. Afterwards, drop into 518 grams of benzoic acid (blocking agent), 253 grams of sodium hypophosphite (catalyst) again, and the solution is delivered to 200 liters of high-pressure reactors. After nitrogen replacement, the temperature of the reaction tank was raised to 230 degrees Celsius for 60 minutes of prepolymerization. Then, set the temperature to 240 degrees, open the exhaust valve, and let the steam out. After the water is completely discharged, it is pumped into the second-stage polycondensation reactor with a gear pump, reacted for 100 minutes at 285 degrees Celsius, and finally collects solid granular products, and the RV test is 2.68. According to the test results, because the evaporation temperature is set too high, it is easy to block before the second-stage polycondensation reactor, and attention should be paid to the length of the delivery pipe from the gear pump to the reactor.

Comparative example 4

Add 90 kg of water, 23.7 kg of adipic acid, 29.2 kg of terephthalic acid, and 42.9 kg of hexamethylenediamine into a 200-liter mixing tank. After starting the stirring, heat up to 85 degrees Celsius and mix for 60 minutes to ensure that the solution is uniform Afterwards, drop into 518 grams of benzoic acid (blocking agent), 253 grams of sodium hypophosphite (catalyst) again, and the solution is delivered to 200 liters of high-pressure reactors. After nitrogen replacement, the temperature of the reaction tank was raised to 240 degrees Celsius for 60 minutes of prepolymerization. Then, set the temperature to 150 degrees, open the exhaust valve, and let the steam out. As a result of the test, because the evaporation temperature was set too low, after the water evaporated, the viscosity of the semi-finished product suddenly increased, causing the stirring blades to be unable to stir, and the semi-finished product could not be discharged.

Based on the above, in the manufacturing method of the high melting point polyamide polymer of the present invention, the evaporation is carried out at 160-230°C, which is less likely to block the pipe fittings. Evaporating at a temperature exceeding 230° C. (such as Comparative Example 3) or lower than 160° C. (such as Comparative Example 4) can improve the reaction efficiency of the polycondensation reactor, but the operation process is prone to blockage. In addition, in the method for producing high-melting-point polyamide polymers of the present invention, the reaction temperature of the polycondensation reaction is at least 20°C lower than the crystallization temperature of the polyamide polymers and lower than the melting temperature of the polyamide polymers, Furthermore, at 260-295°C, molecular cracking caused by high temperature can be avoided, resulting in poor quality, and the temperature is sufficient to maintain the reaction rate, and the required relative viscosity can be achieved without solid-state polymerization. In other words, the present invention can reduce the reaction time, reduce the equipment space, and increase the flexibility of the workshop.

Although the foregoing description and drawings have disclosed preferred embodiments of the present invention, it must be understood that various additions, modifications and substitutions may be applied to the preferred embodiments of the present invention without departing from the scope of the appended application as defined The spirit and scope of the principles of the invention. Those of ordinary skill in the art to which the invention pertains will appreciate that the invention can be employed with many modifications in form, structure, arrangement, proportion, material, element and assembly. Therefore, the embodiments disclosed herein should be regarded as illustrating the present invention rather than limiting the present invention. The scope of the present invention should be defined by the claims of the appended claims and cover their legal equivalents, not limited by the foregoing description.

A1000: Steps A2000: Steps A3000: Steps A4000: Steps A5000: Steps A6000: Steps

Fig. 1 is a schematic flow chart of an embodiment of the present invention.

A1000: Steps

A2000: Steps

A3000: Steps

A4000: Steps

A5000: Steps

A6000: Steps

Claims (9)

A method for producing high-melting polyamide polymers, including the following steps in sequence: (A1000) performing a prepolymerization reaction on an amide salt solution at a temperature of 200-240°C and a pressure of 14.8-33.1 kg/cm ² G (A2000) evaporating the product of the prepolymerization reaction at a temperature of 160-230° C.; and (A3000) performing a polycondensation reaction on the product of the prepolymerization reaction after evaporation in the step A2000, wherein the polycondensation reaction The reaction temperature is at least 20°C lower than the crystallization temperature (Tc) of the polyamide polymer, and lower than the melting temperature (Tm) of the polyamide polymer. The manufacturing method as claimed in item 1, wherein the reaction time of step A1000 is 1 hour. The manufacturing method as described in Claim 1, further comprising: (A4000) The product of the polycondensation reaction is broken into granules. The manufacturing method as described in claim 3, wherein the step A4000 is carried out in a first reactor, and the manufacturing method further comprises: (A5000) Transporting the product of the polycondensation reaction broken into particles to the outside of the first reactor. The manufacture method as claimed in item 1, wherein the amide salt solution comprises: Monobasic acid, calculated in 100 moles; One dibasic amine, the addition amount is 100~110 mol; Blocking agent, added in an amount of 0.1 to 3.0 moles; and A catalyst, the addition amount is 0.1~2 moles. The production method according to claim 5, wherein the dibasic acid is a single aromatic dibasic acid or a mixture of multiple aromatic dibasic acids. The production method according to claim 5, wherein the dibasic acid is a mixture of aromatic dibasic acid and aliphatic dibasic acid, wherein the proportion of aromatic dibasic acid is greater than 45 mol%. The production method as claimed in item 5, wherein the end-capping agent is a compound having a single carboxylic acid and no amine group. The manufacturing method as described in Claim 5, wherein the catalyst is selected from phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof.