JP7055364B2 - Nylon salt powder manufacturing method - Google Patents

Description

The present invention relates to a method for producing a nylon salt powder suitable for producing a copolymerized nylon, and a method for producing a copolymerized nylon using the nylon salt powder produced by the method.

As a method of obtaining nylon from a diamine and a dicarboxylic acid as raw materials, there is a method of reacting a diamine and a dicarboxylic acid to prepare a nylon salt, and solid-phase polymerization or melt polymerization of the obtained nylon salt. By polymerizing the nylon salt in this way, high molecular weight nylon can be stably obtained. Solid phase polymerization of nylon salts is called direct solid phase polymerization.

Various methods for producing nylon salts have been studied. For example, Patent Document 1 discloses a method in which a diamine and a dicarboxylic acid are reacted at a high temperature and a high pressure in the presence of water, and then the reaction product is ejected at a high temperature to separate the water to obtain a nylon salt. Has been done. However, since this method requires a step of ejecting the reaction product at a high temperature and high pressure, there is a problem that the manufacturing equipment becomes large-scale, the step becomes complicated, and the cost increases. Further, when the nylon salt obtained in the presence of water is subjected to solid phase polymerization, the produced nylon becomes gel-like, and the triamine having a branched structure is produced as a by-product, so that the melting point is lowered and the heat resistance is reduced. There is a problem of being inferior to. From the above, it is considered that a method of obtaining a nylon salt powder in the absence of water and polymerizing the powder is ideal as a method for producing nylon.

Patent Document 2 describes a simple method in which the content of water is 5% by mass or less with respect to the total amount of dicarboxylic acid and diamine, and the dicarboxylic acid powder and diamine are reacted while maintaining the powder state. Disclosed is a method for efficiently obtaining a powdered nylon salt. By directly solid-phase polymerizing this powdered nylon salt, nylon having excellent heat resistance and a high molecular weight can be efficiently obtained. The method disclosed in Patent Document 2 can also be applied to copolymerized nylon.
On the other hand, Patent Document 3 also describes a similar method. By using a liquid mixture of diamines, a nylon salt containing a plurality of diamines is formed, and this nylon salt has a reaction rate in direct solid phase polymerization. It is also stated that it will improve.
However, in the direct solid phase polymerization using the nylon salt containing a plurality of diamines, the powder is more likely to consolidate and solidify on the wall surface of the reactor than in the case of the nylon salt containing a single diamine. There was a problem that the operability of the time was inferior. Excessive condensation of powder can cause process problems such as granulation and agglomeration, hindering agitation in the reactor and blockage of pipes. Further, since the nylon having a large particle size is contained, the obtained nylon becomes a problem even in a post-process such as melt molding. Consolidation on the wall surface of the reactor reduces the heat conduction from the reactor to the powder, lowering the polymerization rate, or if the next batch is produced with consolidation still occurring, the heat conduction will decrease. Quality such as molecular weight will fluctuate.

Japanese Unexamined Patent Publication No. 2001-348427 International Publication No. 2012/070457 Special Table 2016-508525 Gazette

The present invention is a method for producing a nylon salt powder containing a plurality of diamines by solving the above problems, and is a nylon salt that does not cause the powder to condense or solidify on the wall surface of the reactor in direct solid phase polymerization. It is an object of the present invention to provide a method for producing a powder, and by using this nylon salt, a method for producing a copolymerized nylon with good operability.

As a result of diligent studies, the present inventor has found that the above problems can be solved by adding a plurality of diamines to a dicarboxylic acid by a specific method, and arrived at the present invention.
That is, the gist of the present invention is as follows.
(1) A method for producing a nylon salt powder containing a dicarboxylic acid and two or more types of diamines, wherein the dicarboxylic acid powder has a temperature equal to or higher than the melting point of the diamine having the highest melting point and a temperature of 210 ° C. or lower. While maintaining the state of the dicarboxylic acid powder by preheating to, the dicarboxylic acid powder is added one by one in the order of increasing the melting point of nylon obtained from the diamine and the dicarboxylic acid . A method for producing a nylon salt powder, which is characterized by being added to .
(2 ) A method for producing a copolymerized nylon, which comprises solid-phase polymerization of the nylon salt powder produced by the method described in (1) above.

According to the production method of the present invention, it is possible to produce a nylon salt powder capable of preventing the powder from consolidating or consolidating on the wall surface of the reactor during direct solid phase polymerization.

The method for producing a nylon salt powder of the present invention uses a dicarboxylic acid powder and two or more kinds of diamines as raw materials.

The dicarboxylic acid used in the powder state in the present invention usually has a melting point of about 120 to 400 ° C. and is not particularly limited. For example, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, oxalic acid and naphthalenedicarboxylic acid. Examples include acids and cyclohexanedicarboxylic acids. Among them, terephthalic acid, isophthalic acid, and adipic acid are preferable from the viewpoint of versatility, and the melting point of the obtained nylon is high, so that the powder state can be easily maintained, and in addition, the heat of reaction during salt formation should be reduced. Terephthalic acid and isophthalic acid are more preferable. The dicarboxylic acid used may be two or more kinds.

The diamine used in the present invention usually has a melting point of about 25 to 200 ° C., and two or more kinds are used. Each diamine is not particularly limited, but is, for example, 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecane. Examples thereof include diamine, 2-methyl-1,5-pentanediamine, p-phenylenediamine, m-xylylenediamine and p-xylylenediamine. Of these, 1,6-hexanediamine, 1,9-nonanediamine, and 1,10-decanediamine are preferable from the viewpoint of versatility. In the present invention, the compounding ratio of two or more kinds of diamines is completely arbitrary.

In the present invention, a nylon salt may be mixed with lactams such as caprolactam and amino acids such as aminocaproic acid, if necessary. The mixing amount may be in a range that does not impair the effects of the present invention, and is preferably 1 to 30 mol%, more preferably 5 to 20 mol% with respect to the dicarboxylic acid, for example.

In the method for producing a nylon salt powder of the present invention, a dicarboxylic acid powder preheated to a temperature equal to or higher than the melting point of diamine having the highest melting point and lower than the melting point of the dicarboxylic acid is used while maintaining this heating temperature. It is necessary to add diamines one by one to the dicarboxylic acid powder and react while maintaining the state of the dicarboxylic acid powder.

In the method for producing a nylon salt powder of the present invention, as described above, it is necessary to preheat the dicarboxylic acid powder as a raw material before adding the diamine.
By heating the dicarboxylic acid powder in advance, there is an advantage that the dicarboxylic acid can be reacted with the diamine while maintaining the powder state. If the dicarboxylic acid powder is not heated in advance, there arises a problem that the obtained nylon salt is agglomerated. That is, when the diamine powder is heated after adding the diamine, the diamine and the dicarboxylic acid do not react with each other under the condition that the temperature is not sufficiently raised at the initial stage of heating, so that a nylon salt is not formed and the liquid diamine is used. It is a mixture of dicarboxylic acid powder in the form of slurry, paste, or clay. When the mixture in such a state is further heated, it becomes a lump nylon salt instead of a powder.

When the dicarboxylic acid powder as a raw material is preheated before the addition of diamine, the heating temperature must be equal to or higher than the melting point of diamine having the highest melting point and lower than the melting point of the dicarboxylic acid constituting the dicarboxylic acid powder. It is preferably at least (melting point of diamine having the highest melting point + 10 ° C.) and at least (melting point of dicarboxylic acid −5 ° C.). If the heating temperature is lower than the melting point of any of the diamines, both the dicarboxylic acid powder and the diamine are in a solid state, and there is a problem that the formation reaction of the nylon salt hardly proceeds. On the other hand, when the heating temperature exceeds the melting point of the dicarboxylic acid, there is a problem that the entire reaction system becomes liquid and the whole reaction system becomes agglomerated with the formation of the nylon salt.
Within the above range, the heating temperature of the dicarboxylic acid powder is preferably 100 ° C. or higher and 210 ° C. or lower, and more preferably 120 ° C. or higher and 200 ° C. or lower. If the heating temperature is less than 100 ° C., the nylon salt formation reaction may be insufficient. On the other hand, when the heating temperature exceeds 210 ° C., an amide formation reaction occurs during the nylon salt formation reaction to generate water, and as a result, the obtained nylon salt is produced due to the generated water. Partially melts and fuses, or the reaction system may become high pressure.

The heating temperature for preheating the dicarboxylic acid powder as a raw material and the reaction temperature for producing the nylon salt may be the same temperature or different temperatures.

The dicarboxylic acid needs to have a powdery form at any stage during the reaction with the diamine. Therefore, when the raw material dicarboxylic acid is in the form of a lump, it is necessary to pulverize it in advance by pulverization or the like before use.

Further, in order to maintain the powdery state of the dicarboxylic acid at any stage during the reaction with the diamine, when the added diamine spreads in the reaction system, it is in the form of a slurry or a paste as a whole. It is necessary that it does not become clay-like. While the diamine is added, the diamine added earlier preferably reacts with the powdered dicarboxylic acid to be in a solid state. In order for the dicarboxylic acid and the obtained solid nylon salt to maintain the powder state, conditions such as the amount of diamine added, the addition rate, the addition method, the heating temperature of the dicarboxylic acid powder, and the reaction time must be appropriately set. Also, it is necessary that the powder is sufficiently agitated.

In the present invention, the term "powder" means that it has a granular form and its volume average particle size is about 5 μm to 2 mm.
In the present invention, as described above, the dicarboxylic acid is maintained in a powder state, and its volume average particle size is preferably 5 μm to 1 mm, more preferably 20 to 200 μm. When the volume average particle size of the dicarboxylic acid is 5 μm to 1 mm, the reaction of the nylon salt can proceed quickly, the scattering of the powder is reduced, and the handling of the powder becomes easy.

The diamine may be added to the dicarboxylic acid as a solid or may be added after being heated and melted as a liquid, but from the viewpoint of reducing the volume average particle size of the obtained nylon salt powder, it is heated. It is preferable to add it after melting it into a liquid.

When diamine is added as a solid, the diamine may be prepared in a container different from the reaction vessel and supplied from the other vessel to the reaction vessel while adjusting the addition rate of the diamine. As the device for pollinating the diamine from another container to the reaction container, a device capable of pollinating without mixing air in the atmosphere is preferable. Examples of such a device include a pollination device provided with a double damper mechanism. Further, when the diamine is added as a solid, the pressure of the other container into which the diamine is charged can be made higher than the pressure of the reaction vessel to prevent the diamine from flowing back from the reaction vessel to the other vessel. can.

On the other hand, when diamine is added as a liquid, the diamine is heated and melted in a container different from the reaction vessel to form a liquid, and then the liquid is sent to the reaction vessel. As the device for sending the diamine to the reaction vessel, a device capable of sending the liquid without mixing the air in the atmosphere is preferable. It is preferable to spray the liquid diamine onto the dicarboxylic acid powder in the form of a spray. Further, it is preferable that the device for sending the liquid diamine is previously put in the phase of the powder of the dicarboxylic acid to be reacted. By doing so, nylon salt powder can be efficiently produced.

The method of adding the diamine is not particularly limited as long as the dicarboxylic acid can maintain the powder state during the reaction. Among them, from the viewpoint of suppressing the obtained nylon salt from becoming lumpy and efficiently performing the formation reaction, a method of continuously adding diamines or a method of dividing diamines and adding appropriate amounts, for example, each of them. A method of intermittently adding 1 to 10% by mass of the total amount of diamine in the above is preferable. Further, a method in which the above methods are combined, such as a method in which an appropriate amount of diamine is intermittently added and then a diamine is continuously added, may be used.

The addition rate of the diamine is preferably 0.07 to 6.7% by mass / min, preferably 0.1 to 3.4% by mass / min, from the viewpoint of stably maintaining the powder state of the dicarboxylic acid. Is more preferable. Here, "mass% / min" is the ratio of diamine added in 1 minute to the total amount of diamine finally added. The addition rate may be changed in the middle or may be changed for each type of diamine.

In the present invention, the first diamine is added to the dicarboxylic acid by the above method, then the second diamine, the third diamine and the like are added, and the diamines are added to the dicarboxylic acid powder one by one. In the present invention, it is necessary to start the addition of the next type of diamine after the addition of one type of diamine is completed, instead of adding two or more types of diamines in a mixed manner or at the same time. Is. It is necessary to add one diamine at a time, no matter how many diamines there are.
When changing the type of diamine, allow time for no diamine to be added in order to make the reaction of the previous diamine more complete after the addition of the previous diamine is completed and before the addition of the later diamine is started. Is preferable. This time is preferably 0 to 3 hours, more preferably 0 to 1.5 hours.
After adding the first diamine to the dicarboxylic acid, the addition of the second diamine, the third diamine and the like may be carried out by the same method as the above-mentioned diamine addition method.
The order in which each diamine is added is preferably such that the addition of the diamine that gives nylon having a high melting point is the rearward. For example, in the case of producing a nylon salt for polymerizing a copolymerized nylon 410 / T, the melting point of nylon 4T is 299 ° C. and the melting point of nylon 10T is 274 ° C. After adding the diamine to the dicarboxylic acid, it is preferable to add butanediamine, which gives nylon 4T having a high melting point, to the dicarboxylic acid. The nylon salt obtained by adding a diamine that gives a high melting point nylon at the rear has a further enhanced effect of not causing the condensation of powder or the consolidation to the wall surface of the reactor in direct solid phase polymerization. ..

The total time for adding all kinds of diamines is preferably 0.25 to 24 hours, preferably 0.6 to 10 hours, from the viewpoint of reducing the particle size of the obtained nylon salt powder. More preferred.
Furthermore, it is preferable to allow time for the reaction to be more complete even after the addition of all types of diamines. This time is preferably 0 to 6 hours, more preferably 0.25 to 3 hours.

In the method for producing a nylon salt of the present invention, the molar ratio of the functional group of the carboxylic acid and the amine (dicarboxylic acid) including the dicarboxylic acid and each diamine, and when monocarboxylic acid or monoamine is used as the terminal blocking agent described later. The acid powder / diamine) is preferably 45/55 to 55/45, more preferably 50/50 to 45/55. By controlling the molar ratio of the dicarboxylic acid powder and the diamine within the above range, a nylon salt powder capable of obtaining a high molecular weight nylon can be obtained. Considering the volatilization of diamine in the polymerization step, it is often done to slightly increase the molar ratio of amines.

In the method for producing nylon salt powder of the present invention, from the viewpoint of improving the efficiency of the nylon salt production reaction, in addition to the dicarboxylic acid powder and diamine, the effect of the present invention is not impaired when the raw material is supplied to the reaction vessel. , End sealant, polymerization catalyst may be added.

The terminal blocker seals the end of the terminal functional group of the polymer. Examples of such terminal blockers include acetic acid, lauric acid, stearic acid, benzoic acid, octylamine, cyclohexylamine, aniline and the like. The amount of the terminal sequestering agent used is preferably 5 mol% or less with respect to the total number of moles of the dicarboxylic acid powder and the diamine, which are raw material monomers.

Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts thereof. If the amount of the polymerization catalyst used is too large, it causes deterioration of the performance and processability of the product. Therefore, it is preferably 2 mol% or less with respect to the total number of moles of the dicarboxylic acid powder and the diamine which are the raw material monomers.

Further, in the method for producing a nylon salt powder of the present invention, various additives may be added at any stage as long as the effects of the present invention are not impaired. Examples of the additive include an inorganic filler, a filler, a stabilizer and the like. The amount of the additive used is preferably 20% by mass or less with respect to the total mass of the dicarboxylic acid powder and the diamine, which are raw material monomers, from the viewpoint of not hindering the contact between the diamine and the dicarboxylic acid powder.

In the method for producing a nylon salt powder of the present invention, when the raw material is charged, the water content is preferably 5% by mass or less with respect to the total amount of the dicarboxylic acid powder and the diamine which are the raw materials, and 1% by mass. % Or less, more preferably 0.5% by mass or less, particularly preferably 0.3% by mass or less, further preferably 0.2% by mass or less, and 0% by mass. % Is the most preferable. If the charged raw material contains water, there is a problem that the produced nylon salt is partially melted and fused, or the reaction system becomes high pressure.

In the method for producing a nylon salt powder of the present invention, in order to completely carry out the nylon salt formation reaction, it is preferable to sufficiently stir during the addition of the diamine and after the addition of the diamine is completed. The stirring mechanism provided in the reaction device for reacting the dicarboxylic acid powder with the diamine may be appropriately selected according to the type and production amount of the nylon salt to be produced, and is a blender such as a paddle type, a tumbler type, or a ribbon type. Examples include mixers. Further, a combination of these may be used.

In the above reaction apparatus, the method of heating the dicarboxylic acid powder before the reaction or heating the reaction system during the production reaction is not particularly limited, and heating is performed using a heat medium such as steam, a heater, or the like. There is a way to do it.

In the method for producing a nylon salt powder of the present invention, the reaction between the dicarboxylic acid powder and the diamine may be carried out in air or in an atmosphere of an inert gas such as nitrogen. In order to suppress side reactions and coloring, it is preferable to carry out in an inert gas atmosphere. In addition, the reaction can be carried out in a closed state or under the flow of an inert gas.

In the method for producing nylon salt powder of the present invention, the production rate of nylon salt is preferably 90% or more, more preferably 95% or more. When the production rate of the nylon salt is 90% or more, the amount of unreacted diamine that becomes vapor and disperses is reduced, so that there is an advantage that it becomes easy to obtain high molecular weight nylon.

The volume average particle size of the obtained nylon salt powder is preferably 2 mm or less, more preferably 500 μm or less. By setting the volume average particle size of the nylon salt powder to 2 mm or less, even if water is generated when the nylon salt powder is polymerized to obtain nylon, the water inside the nylon salt is easily removed, so that an amidation reaction is carried out. It has the advantage of being able to increase the speed of.

In the method for producing a nylon salt powder of the present invention, the dicarboxylic acid powder and the diamine are reacted at a temperature equal to or lower than the melting point of the dicarboxylic acid constituting the dicarboxylic acid powder, so that the obtained nylon salt does not agglomerate. It can be a powder. Even if water is generated when the powdered nylon salt is polymerized to obtain a copolymerized nylon, the water inside the nylon salt can be easily removed, so that the speed of the amidation reaction can be increased. It is also possible to suppress the generation of triamine, which is a by-product of the branched structure. Therefore, it can also be suitably used when producing a nylon salt which is difficult to polymerize by melt polymerization due to raw materials and additives.

Further, since the method for producing nylon salt powder of the present invention does not substantially use water, it is not necessary to provide a step of distilling off water. Therefore, the number of steps can be reduced as compared with the manufacturing method in which water is added.

Next, the method for producing the copolymerized nylon of the present invention will be described.
By polymerizing the nylon salt powder produced by the above method, a copolymerized nylon can be obtained with good operability.

In the method for producing a copolymerized nylon of the present invention, a copolymerized nylon is obtained by solid phase polymerization using the nylon salt powder obtained by the above-mentioned method for producing a nylon salt powder. The nylon salt of the present invention can be used for melt polymerization, but the effect of operability may not be obtained.

When the copolymerized nylon is produced by solid phase polymerization, the polymerization conditions are not particularly limited, but the reaction temperature is preferably 180 ° C. or higher and lower than the melting point of the copolymerized nylon, and 200 ° C. or higher and lower than the melting point of the copolymerized nylon. Is more preferable. The reaction time is preferably 0.5 to 100 hours, more preferably 0.5 to 24 hours after reaching the reaction temperature. The solid phase polymerization may be carried out in an inert gas stream such as nitrogen, or may be carried out under reduced pressure. Further, it may be performed stationary or may be performed while stirring.

By solid-phase polymerization of the nylon salt of the present invention, it becomes possible to suppress the condensation of powder and the consolidation to the wall surface of the reaction apparatus, and to produce the copolymerized nylon with good operability.

Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited thereto.
The physical properties of the nylon salt and the copolymerized nylon were measured by the following methods.

(1) Volume average particle size of powder The measurement was performed using a laser diffraction / scattering type particle size distribution measuring device (“LA920” manufactured by HORIBA, Ltd.).

(2) Relative Viscosity of Copolymerized Nylon Copolymerized nylon was dissolved in 96% sulfuric acid to prepare a sample solution having a concentration of 1 g / dl. Using a Ubbelohde viscometer, the drop time of the sample solution and the solvent was measured at a temperature of 25 ° C., and the relative viscosity was determined using the following formula.
Relative viscosity = (falling time of sample solution) / (falling time of solvent only)

(3) Amount of nylon agglomerates 100 g of copolymerized nylon powder was sieved with a mesh opening of 4.75 mm, and the percentage of the amount remaining on the sieve was taken as the amount of agglomerates.

The raw materials used in the examples and comparative examples are as follows.
-TPA: terephthalic acid, melting point 300 ° C or higher, volume average particle size 80 μm
DA: 1,10-decanediamine (melting point of nylon 10T is 274 ° C)
HA: 1,6-hexanediamine (melting point of nylon 6T is 290 ° C)
BA: 1,4-butanediamine (melting point of nylon 4T is 299 ° C)
・ SHP: Sodium hypophosphate monohydrate ・ STA: Stearic acid

Example 1
(Manufacturing of nylon salt powder)
A mixture consisting of 14.6 kg (87.7 mol) of TPA powder, 46.5 g (0.44 mol) of SHP as a polymerization catalyst, and 699 g (2.46 mol) of STA as a terminal sealant was added to a ribbon blender type reactor. It was supplied and heated to 165 ° C. under a nitrogen stream with stirring at a rotation speed of 30 rpm.
Then, 12.5 kg (72.8 mol) of DA heated to 110 ° C. was added to the TPA powder continuously maintained at 165 ° C. over 128 minutes using a liquid feeder at a rate of 98 g / min. Ten minutes after the completion of DA addition, 2.14 kg (18.4 mol) of HA heated to 110 ° C. was continuously applied at a rate of 98 g / min over 22 minutes using a liquid feeder. Added.
After adding all the diamines, stirring was continued for another 30 minutes to obtain the first batch of nylon salt powder.
Subsequently, a second batch of nylon salt powder was obtained by the same method.

(Manufacturing of copolymerized nylon 1)
The obtained first batch of nylon salt powder was heated to 250 ° C. in another ribbon blender type reactor under a nitrogen stream at a rotation speed of 40 rpm with stirring. The reaction was continued for 8 hours as it was, and after cooling, it was dispensed to obtain nylon 610 / T. The metal surface of the inner wall of the reaction apparatus after the polymerization was well exposed, and no adhesive layer was formed. The obtained nylon 610 / T had a relative viscosity of 2.65 and a melting point of 293 ° C. The amount of nylon agglomerates was 0.8%.
(Manufacturing of copolymerized nylon 2)
Further, in order to evaluate the continuous productivity, the reaction apparatus was not cleaned, the nylon salt powder of the second batch was added, and the second polymerization was carried out at 250 ° C. for 8 hours in the same manner. The obtained nylon 610 / T had a relative viscosity of 2.66, a melting point of 293 ° C., and a nylon agglomerate amount of 0.9%, which were the same quality as the first time.

Example 2
(Manufacturing of nylon salt powder)
A mixture consisting of 14.6 kg (87.7 mol) of TPA powder, 46.5 g (0.44 mol) of SHP as a polymerization catalyst, and 699 g (2.46 mol) of STA as a terminal sealant was added to a ribbon blender type reactor. It was supplied and heated to 165 ° C. under a nitrogen stream with stirring at a rotation speed of 30 rpm.
Then, 2.14 kg (18.4 mol) of HA heated to 110 ° C. was added to the TPA powder continuously maintained at 165 ° C. over 22 minutes using a liquid feeder at a rate of 98 g / min. Ten minutes after the completion of the addition of HA, 12.5 kg (72.8 mol) of DA heated to 110 ° C. was continuously applied at a rate of 98 g / min over 128 minutes using a liquid feeder. Added.
After adding all the diamines, stirring was continued for another 30 minutes to obtain the first batch of nylon salt powder.
Subsequently, a second batch of nylon salt powder was obtained by the same method.

(Manufacturing of copolymerized nylon 1)
The obtained first batch of nylon salt powder was heated to 250 ° C. in another ribbon blender type reactor under a nitrogen stream at a rotation speed of 40 rpm with stirring. The reaction was continued for 8 hours as it was, and after cooling, it was dispensed to obtain nylon 610 / T. The metal surface of the inner wall of the reaction apparatus after the polymerization was well exposed, and no adhesive layer was formed. The obtained nylon 610 / T had a relative viscosity of 2.64 and a melting point of 293 ° C. The amount of nylon agglomerates was 3.6%.
(Manufacturing of copolymerized nylon 2)
Further, in order to evaluate the continuous productivity, the reaction apparatus was not cleaned, the nylon salt powder of the second batch was added, and the second polymerization was carried out at 250 ° C. for 8 hours in the same manner. The obtained nylon 610 / T had a relative viscosity of 2.62, a melting point of 294 ° C., and a nylon agglomerate amount of 3.7%, which were the same quality as the first time.

Example 3
(Manufacturing of nylon salt powder)
A mixture consisting of 15.3 kg (92.2 mol) of TPA powder, 53.0 g (0.46 mol) of SHP as a polymerization catalyst, and 734 g (2.58 mol) of STA as a terminal sealant was added to a ribbon blender type reactor. It was supplied and heated to 165 ° C. under a nitrogen stream with stirring at a rotation speed of 30 rpm.
Then, 8.11 kg (47.0 mol) of DA heated to 110 ° C. was added to the TPA powder continuously maintained at 165 ° C. over 128 minutes using a liquid feeder at a rate of 88 g / min. Ten minutes after the completion of DA addition, then 5.79 kg (49.8 mol) of BA heated to 110 ° C. was continuously applied at a rate of 93 g / min over 62 minutes using a liquid feeder. Added.
After adding all the diamines, stirring was continued for another 30 minutes to obtain the first batch of nylon salt powder.
Subsequently, a second batch of nylon salt powder was obtained by the same method.

(Manufacturing of copolymerized nylon 1)
The obtained first batch of nylon salt powder was heated to 245 ° C. in another ribbon blender type reactor under a nitrogen stream at a rotation speed of 40 rpm with stirring. The reaction was continued for 9 hours as it was, and after cooling, it was dispensed to obtain nylon 410 / T. The metal surface of the inner wall of the reaction apparatus after the polymerization was well exposed, and no adhesive layer was formed. The obtained nylon 410 / T had a relative viscosity of 2.45 and a melting point of 301 ° C. The amount of nylon agglomerates was 1.2%.
(Manufacturing of copolymerized nylon 2)
Further, in order to evaluate the continuous productivity, the reaction apparatus was not cleaned, the nylon salt powder of the second batch was added, and the second polymerization was carried out at 250 ° C. for 9 hours in the same manner. The obtained nylon 410 / T had a relative viscosity of 2.44, a melting point of 300 ° C., and a nylon agglomerate amount of 1.1%, which were the same quality as the first time.

Comparative Example 1
(Manufacturing of nylon salt powder)
A mixture consisting of 14.6 kg (87.7 mol) of TPA powder, 46.5 g (0.44 mol) of SHP as a polymerization catalyst, and 699 g (2.46 mol) of STA as a terminal sealant was added to a ribbon blender type reactor. It was supplied and heated to 165 ° C. under a nitrogen stream with stirring at a rotation speed of 30 rpm.
Then, a mixture of 12.5 kg (72.8 mol) of DA and 2.14 kg (18.4 mol) of HA was heated to 110 ° C. at a rate of 98 g / min over 150 minutes using a liquid feeder. It was added to the TPA powder which was continuously maintained at 165 ° C.
After adding the diamine, stirring was further continued for 30 minutes to obtain the first batch of nylon salt powder.
Subsequently, a second batch of nylon salt powder was obtained by the same method.

(Manufacturing of copolymerized nylon 1)
The obtained first batch of nylon salt powder was heated to 250 ° C. in another ribbon blender type reactor under a nitrogen stream at a rotation speed of 40 rpm with stirring. The reaction was continued for 8 hours as it was, and after cooling, it was dispensed to obtain nylon 610 / T. The inner wall of the reaction apparatus after the polymerization was covered with an adhering layer of the consolidated nylon powder. The obtained nylon 610 / T had a relative viscosity of 2.51 and a melting point of 294 ° C. The amount of nylon agglomerates was 19.5%, which was considerably large.
(Manufacturing of copolymerized nylon 2)
Further, in order to evaluate the continuous productivity, the reaction apparatus was not cleaned, the nylon salt powder of the second batch was added, and the second polymerization was carried out at 250 ° C. for 8 hours in the same manner. The obtained nylon 610 / T had a relative viscosity of 2.09, which was quite different from the first time. The melting point was 293 ° C., and the amount of nylon agglomerates was 21.7%.

Comparative Example 2
(Manufacturing of nylon salt powder)
A mixture consisting of 15.3 kg (92.2 mol) of TPA powder, 53.0 g (0.46 mol) of SHP as a polymerization catalyst, and 734 g (2.58 mol) of STA as a terminal sealant was added to a ribbon blender type reactor. It was supplied and heated to 165 ° C. under a nitrogen stream with stirring at a rotation speed of 30 rpm.
Then, a mixture of 8.11 kg (47.0 mol) of DA and 5.79 kg (49.8 mol) of BA was heated to 110 ° C. at a rate of 93 g / min over 150 minutes using a liquid feeder. It was added to the TPA powder which was continuously maintained at 165 ° C.
After adding all the diamines, stirring was continued for another 30 minutes to obtain the first batch of nylon salt powder.
Subsequently, a second batch of nylon salt powder was obtained by the same method.

(Manufacturing of copolymerized nylon 1)
The obtained first batch of nylon salt powder was heated to 245 ° C. in another ribbon blender type reactor under a nitrogen stream at a rotation speed of 40 rpm with stirring. The reaction was continued for 9 hours as it was, and after cooling, it was dispensed to obtain nylon 410 / T. The inner wall of the reaction apparatus after the polymerization was covered with an adhering layer of the consolidated nylon powder. The obtained nylon 410 / T had a relative viscosity of 2.36 and a melting point of 303 ° C. The amount of nylon agglomerates was 27.5%, which was considerably large.
(Manufacturing of copolymerized nylon 2)
Further, in order to evaluate the continuous productivity, the reaction apparatus was not cleaned, the nylon salt powder of the second batch was added, and the second polymerization was carried out at 250 ° C. for 9 hours in the same manner. The obtained nylon 410 / T had a relative viscosity of 1.99, which was considerably different from the first time. The melting point was 301 ° C., and the amount of nylon agglomerates was 33.4%.

Table 1 shows the production conditions of the nylon salt powder, the solid phase polymerization conditions, and the characteristics of the obtained copolymerized nylon.

The nylon salt powder of the example produced by adding one type of diamine to the dicarboxylic acid powder does not cause the powder to condense or solidify on the wall surface of the reactor in the solid phase polymerization, and has good operability. It was possible to produce a copolymerized nylon in. Further, the nylon salt powders of Examples 1 and 3 obtained by later adding diamine that gives nylon having a high melting point to the dicarboxylic acid are the nylon salt powders of Example 2 in which the order of adding diamines is reversed. The amount of agglomerates generated in the solid phase polymerization was smaller than that of the above.
When the nylon salt powder of the comparative example produced by mixing two types of diamines and adding them to the dicarboxylic acid powder was subjected to solid phase polymerization, the inner wall of the reaction apparatus was covered with an adhering layer of the solidified copolymer nylon powder. The obtained copolymerized nylon contained a large amount of agglomerates. Further, when the nylon salt powder was solid-phase polymerized in the reaction apparatus in which the inner wall was covered with the adhered layer of the copolymerized nylon powder solidified, the relative viscosity of the obtained copolymerized nylon was remarkably lowered.

Claims (2)

A method for producing a nylon salt powder containing a dicarboxylic acid and two or more types of diamines, wherein the dicarboxylic acid powder is preheated to a temperature equal to or higher than the melting point of the diamine having the highest melting point and to a temperature of 210 ° C. or lower. Then, while maintaining this heating temperature and maintaining the state of the dicarboxylic acid powder, diamine is added to the dicarboxylic acid powder one by one in the order of increasing the melting point of the nylon obtained from the diamine and the dicarboxylic acid . A method for producing a nylon salt powder. A method for producing a copolymerized nylon, which comprises solid-phase polymerization of the nylon salt powder produced by the method according to claim 1 .