KR101723627B1 - Method for preparing of polyamide resin and polyamide resin - Google Patents

Abstract

The present invention relates to a process for producing a polyamide resin and a polyamide resin, which comprises a lactam polymerization step of polymerizing lactam having 5 to 7 carbon atoms at 250 to 280 ° C to produce a polymer, And a pyrrolidone polymerization step of polymerizing pyrrolidone (2-pyrrolidone) at 130 to 200 DEG C to prepare a copolymer.
The method of producing the polyamide resin can produce a polyamide resin improved in spinnability and heat resistance by inducing a decrease in melting point and an increase in thermal decomposition temperature while maintaining super absorbency, and the production of nylon 6 fibers It is economical to use facilities.

Description

METHOD FOR PREPARING POLYAMIDE RESIN AND POLYAMIDE RESIN BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method for producing a polyamide resin and a polyamide resin. More particularly, the present invention relates to a polyamide resin which is capable of retaining various properties such as light weight, warmth, high sensitivity, antibacterial property, quick- Amide resin and a polyamide resin.

Nylon 6 fibers generally have excellent stiffness, elastic recovery and dyeability, but most synthetic fibers, including nylon 6 fibers, have a low water absorbency. Cotton which is a natural fiber is excellent in absorbency and good in touch compared to conventional synthetic fibers, but it can not be processed by microfibers, so it can not produce excellent tactile sensation and it is very insufficient in UV blocking property and its price is high. Therefore, the appearance of innovative nylon synthetic fiber I have been desperate.

For those who have been studying polymers and synthetic fibers for a long time, we have researched the new synthetic fibers, which can be called dreamy synthetic fibers, which can save the advantages of conventional absorbent cotton and excellent comfort. come. It is nylon 4 that has received the most attention among the fruits of such efforts.

In general, the water absorption of crystalline polymer depends on various factors such as hydrophilic functional group type, crystal structure and crystallinity. In the case of nylon, one of the crystalline polymers, if the number of the lipophilic carbon atoms relative to the amide group which is hydrophilic in the repeating unit of polymer is decreased, In view of the fact that the hydrophilicity will increase and the absorbency will increase, studies on nylon 3 or nylon 4 with a lower carbon number compared to nylon 6 have been conducted in depth.

As with other nylons, the nylon 4, which has received the most interest, can be synthesized by heating and dehydrating the raw monomer GABA (gamma amino butyric acid), but the monomer itself is cyclized to become 2-pyrrolidone Therefore, the polymer can not be obtained. In addition, 2-pyrrolidone is thermally stable because it is a 5-ring cycled, and ring-opening polymerization is also difficult.

In 1953, Ney et al. Succeeded in the synthesis of nylon 4 for the first time by dehydration by heating under reduced pressure at 90 to 120 캜 using potassium hydroxide and heating at 160 캜 under nitrogen flow to synthesize nylon 4. In 1956, when metal potassium was used as a basic catalyst and a compound having an acyl group was used as an activating agent, ring opening polymerization proceeded rapidly at 40 ° C to obtain nylon 4. Based on this method, technologies such as new catalyst systems and polymerization methods have been developed for the purpose of high molecular weight, polydispersity control, and simplification of the manufacturing process from the 1950s to the 1990s.

Polymerization of nylon 4 resin and fabrication of fibers using the same was actively carried out by Chevron Research from the 1970s to 1980s, mainly on the pilot scale, catalytic studies, polymerization process studies, thermal stabilization studies, But it did not succeed in commercialization.

In addition, the poly (2-pyrrolidone) resin synthesized in 1953 has superior absorbability and rigidity due to the small number of lipophilic carbon atoms per repeating unit in its structure. In 1973, Although synthetic resin has appeared spectacularly in history, there is a technical problem that the melting point is 265 ° C, while the pyrolysis temperature is 260 ° C, which is extremely poor in spinning heat resistance. At this time, the high price of the monomer 2-pyrrolidone, For 30 years, it has been commercially unsuccessful and has been implicated in history.

It is an object of the present invention to provide a polyamide resin having improved radial processability and heat resistance by lowering the melting point and raising the pyrolysis temperature while maintaining ultrahigh absorbency and using a manufacturing facility such as nylon 6 fiber And a method for producing the polyamide resin.

The present invention provides a polyamide resin produced by the process for producing a polyamide resin.

In order to achieve the above object, a method for producing a polyamide resin according to an embodiment of the present invention includes a lactam polymerization step of polymerizing lactam having 5 to 7 carbon atoms at 250 to 280 ° C, And polymerizing the polymer and 2-pyrrolidone at 130 to 200 캜 to produce a copolymer.

The content of the 2-pyrrolidone in the polyamide resin may be 30 mol% or more with respect to the total amount of the polyamide resin.

The polyamide resin may have a relative viscosity (RV) value of 1.9 or more.

Wherein any one step selected from the group consisting of the lactam polymerization step, the pyrrolidone polymerization step and a combination thereof is a step of reacting water with 100 moles of the monomer containing 2-pyrrolidone and the lactam having 5 to 7 carbon atoms as a catalyst, 20 to 200 parts by mole.

The method for producing the polyamide resin may further include discharging and chipping the produced copolymer at 200 ° C or lower.

A method for producing a polyamide resin according to another embodiment of the present invention includes a pyrrolidone polymerization step of polymerizing 2-pyrrolidone at 130 to 200 ° C to prepare a polymer, And a lactam polymerization step in which a lactam having 5 to 7 carbon atoms is polymerized at 250 to 280 DEG C to prepare a copolymer.

A polyamide resin according to another embodiment of the present invention is a copolymer of lactam having 2 to 7 carbon atoms and 2-pyrrolidone, wherein the content of the 2-pyrrolidone is not less than 30 mol% .

The polyamide resin may have a relative viscosity (RV) value of 1.9 or more.

Hereinafter, the present invention will be described in more detail.

The method for producing a polyamide resin according to an embodiment of the present invention can produce a nylon resin capable of maximally improving the ultrahigh absorptivity, which is the strength of the nylon 4 resin, and at the same time improving radiant heat resistance, 2-pyrrolidone-co-caprolactam) copolymer and the like.

Nylon 4 has a melting point of 265 ° C which is higher than that of nylon 6, while a pyrolysis temperature of 260 ° C is required for melt spinning at temperatures above the melting point due to the nature of spinning. During this process, the nylon 4 polymer is pyrolyzed, .

Generally, pyrolysis of polymers can be divided into chain depolymerization and random decomposition. The former is a mechanism in which electrons disappear chainwise at the terminal of the chain or at weak bonding sites, Refers to the mechanism by which random cleavage takes place anywhere in the chain. Generally, condensation polymers such as nylon are dominant in random pyrolysis, but two mechanisms are combined. Further, when water is present at a high temperature, pyrolysis can be accelerated due to hydrolysis of the amide bond.

Generally, when nylon is pyrolyzed at high temperature, production of CO ₂ , H ₂ O or NH ₃ is increased mainly by decarboxylation reaction and deamination reaction. In addition, water may be produced by condensation and dehydration, and polymeric amines and nitriles may also be produced.

In addition, when the nylon resin is heated to a high temperature in an oxygen-containing atmosphere, oxidation pyrolysis reaction occurs, and a trace amount of impurities such as metal ions, carbonyl compounds, hydroperoxides, Absorbing to generate free radicals (stray free radicals) to initiate the chain reaction. In the case of nylon, the reaction starts mainly on the methylene group attached to the amide nitrogen, that is, the α-carbon. The free radicals first strip hydrogen to form carbon radicals, which are then combined with oxygen to form peroxy radicals. This leads to a chain reaction by releasing hydrogen again from the polymer chain to produce hydroperoxides and another alkyl radical. Hydroperoxides are degraded to form alkoxy radicals and hydroxyl radicals and to initiate a new chain reaction.

On the other hand, pyrolysis causing yellowing of the nylon resin is largely due to the formation of unsaturated conjugated oligoenimine. Enimine absorbs ultraviolet light and visible light and is colored. Over time, the more conjugation proceeds and the more conjugation, the longer wavelengths of light are absorbed and the yellowing becomes more severe. Oligonemines are made by the reaction of an amine end group with an aldehyde.

In the case of nylon 4, heat resistance is more problematic in that the equilibrium between the polymer and the monomer in the molten state is toward the monomer. For these reasons, factors affecting the thermal stability of the nylon 4 polymer include end groups, impurities in the polymerization catalyst, molecular weight distribution, presence or absence of side chains, and irregularities in the structure.

The method for producing the polyamide resin is a method for producing a polyamide resin which is a copolymer of 2-pyrrolidone and lactam having 5 to 7 carbon atoms in order to maximize ultra-high water absorption, which is the strength of nylon 4 resin, . The copolymers of 2-pyrrolidone and lactam differ in important physical properties such as water absorbency, melting point, and thermal decomposition temperature depending on the kind and composition of the constituent materials, so that it is possible to simultaneously secure ultrahigh absorbency and radiation heat resistance by appropriately controlling them.

The method for producing the polyamide resin includes a lactam polymerization step of polymerizing lactam having a carbon number of 5 to 7 at 250 to 280 ° C. and a step of polymerizing the polymer and 2-pyrrolidone And polymerizing at 130 to 200 캜 to produce a copolymer.

Alternatively, the polyamide resin may be prepared by polymerizing 2-pyrrolidone at 130 to 200 ° C to prepare a polymer. The polymer is reacted with a lactam having 5 to 7 carbon atoms in an amount of 250 - And then polymerized at 280 ° C to prepare a copolymer.

The most promising way to dramatically improve the heat resistance of nylon 4 is to produce copolymers. In other words, the spinnability and heat resistance of nylon 4 can be improved by changing the molecular structure by copolymerizing with some other raw materials although the main component is 2-pyrrolidone capable of exhibiting super absorbent properties, have. That is, through the copolymerization, it is possible to induce the lowering of the melting point of the nylon 4 and the increase of the thermal decomposition temperature. Particularly, in order to use a manufacturing facility such as nylon 6 fiber, which has already been invested in terms of economy, it is preferable to produce a nylon-based copolymer having a melting point close to nylon 6 or the like.

However, when nylon 4 is polymerized by a general nylon 6 polymerization method, the higher the content of 2-pyrrolidone is, the more the reaction according to the polymerization method of nylon 6 proceeds to the reaction temperature of nylon 4, .

The polyamide resin may be prepared by polymerizing 2-pyrrolidone or 2-pyrrolidone at a different temperature, or by polymerizing 2-pyrrolidone and then polymerizing the lactam. It is possible to produce a polyamide resin having a high content of pyrrolidone and improved spinning and heat resistance.

Accordingly, the production method of the above-mentioned polyamide resin can be carried out by using the nylon 6 production equipment which has already been invested, and is excellent in terms of economy.

The content of the 2-pyrrolidone in the polyamide resin produced by the process for producing a polyamide resin may be 30 mol% or more, preferably 40 mol% or more and less than 100 mol% have. The method for producing the polyamide resin is capable of producing a polyamide resin having a high content of 2-pyrrolidone having a content of 2-pyrrolidone of 30 mol% or more. It is a matter of course that a polyamide resin having a content of 2-pyrrolidone of less than 30 mol% can also be produced.

The polyamide resin can change physical properties by controlling the ratio of 2-pyrrolidone to lactam having 5 to 7 carbon atoms. The polyamide resin having a content of 2-pyrrolidone of 30 mol% But the heat resistance of the spinning process is greatly improved.

In the lactam polymerization step, the reaction temperature may be 250 to 280 ° C. If the reaction temperature is lower than 250 ° C., the polymerization reaction of the lactam does not proceed well, and a larger amount of unreacted material than the polyamide resin can be formed. ° C, the resulting polymer may be pyrolyzed.

In addition, the lactam polymerization step may be carried out for 2 to 5 hours, preferably 2 to 4 hours. If the reaction time is less than 2 hours, the polymerization reaction of the lactam does not proceed well, and a larger amount of unreacted materials than the polyamide resin can be formed. If the reaction time exceeds 5 hours, the resulting polymer may be thermally decomposed.

The lactam polymerization step may be carried out under a pressure of 5 atm or more, preferably 6 to 10 atm. The higher the reaction pressure, the more the reactivity can be improved, and the reactivity can be improved at a minimum process cost of 5 atm or more. If the reaction pressure exceeds 10 atm, a problem may arise in the manufacturing equipment.

In the pyrrolidone polymerization step, the reaction temperature may be 130 to 200 ° C, preferably 140 to 190 ° C. If the reaction temperature is lower than 130 ° C, the polymerization reaction of the 2-pyrrolidone proceeds insufficiently and a larger amount of unreacted materials than the polyamide resin can be formed. If the reaction temperature exceeds 200 ° C, the resulting polymer may be thermally decomposed.

In addition, the pyrrolidone polymerization step may be performed for 1 to 5 hours, preferably for 2 to 4 hours. If the reaction time is less than 1 hour, the polymerization reaction of the pyrrolidone proceeds insufficiently and a larger amount of unreacted material than the polyamide resin can be formed. If the reaction time exceeds 5 hours, the resulting polymer may be thermally decomposed.

The pyrrolidone polymerization step may be performed at a pressure of 5 atm or more, preferably 6 to 10 atm. The higher the reaction pressure, the more the reactivity can be improved, and the reactivity can be improved at a minimum process cost of 5 atm or more. If the reaction pressure exceeds 10 atm, a problem may arise in the manufacturing equipment.

The polyamide thus produced may have a weight average molecular weight of 10,000 to 50,000, preferably 10,000 to 30,000. The polyamide resin may have a relative viscosity (RV) value of 1.9 or more, preferably 2.0 or more. When the weight average molecular weight of the polyamide and the relative viscosity value are out of the above range, it is difficult to say that a polymer having a sufficient size is produced, so that chip formation is impossible and ejection may be non-uniform.

Any one step selected from the group consisting of the lactam polymerization step, the pyrrolidone polymerization step, and combinations thereof can be used as a catalyst. The water is a catalyst used in the production of nylon 6. The method of producing the polyamide resin is not a catalyst used in the production of nylon 4 conventionally but also a catalyst used in the production of nylon 6, It is possible to prepare the polyamide as a copolymer. This applies not only when the content of 2-pyrrolidone is small, but also when the content of 2-pyrrolidone is 30 mol% or more. Accordingly, the production method of the polyamide resin has an advantage that the conventional nylon 6 production facility can be used as it is in the production of a polyamide resin having a high content of 2-pyrrolidone.

The water may be used in an amount of 20 to 200 moles, preferably 50 to 150 moles, more preferably 70 to 120 moles per 100 moles of the monomer containing the 2-pyrrolidone and the lactam having 5 to 7 carbon atoms. If the content of water is less than 20 parts by weight, the lactam polymerization may not be carried out. If the amount of water is more than 200 parts by weight, the produced polyamide may be decomposed due to excessive use of the catalyst. When the content of the water is 70 to 120 moles, the amount of the catalyst relative to the monomer is appropriate, thereby maximizing the reactivity.

The prepared copolymer may be discharged and chips at a temperature of 200 ° C or lower to obtain a polyamide resin. The polyamide resin produced according to the method for producing a polyamide resin may have a low viscosity, so that the discharge temperature is preferably 200 ° C or less in order to facilitate discharge.

The polyamide resin according to another embodiment of the present invention is a copolymer of lactam having 2 to 7 carbon atoms and 2-pyrrolidone, wherein the content of the 2-pyrrolidone is not less than 30 mol% , Preferably from 40 mol% to less than 100 mol%.

According to the method for producing a polyamide resin, a polyamide resin having a content of 2-pyrrolidone of 30 mol% or more with respect to the total amount of the polyamide resin can be produced. The content of the 2-pyrrolidone in the polyamide resin is 30 mol% or more, and the nylon 4 is excellent in spinning heat resistance while maintaining super absorbency.

The polyamide may have a weight average molecular weight of 10,000 to 50,000, preferably 10,000 to 30,000. The polyamide resin may have a relative viscosity (RV) value of 1.9 or more, preferably 2.0 or more. When the weight average molecular weight of the polyamide and the relative viscosity value are out of the above range, it is difficult to say that a polymer having a sufficient size is produced, so that chip formation is impossible and ejection may be non-uniform.

The method of producing a polyamide resin according to an embodiment of the present invention can produce a polyamide resin improved in spinnability and heat resistance by inducing a decrease in melting point and an increase in thermal decomposition temperature while maintaining super absorbency, It is economical to use a manufacturing facility of nylon 6 fiber or the like.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[Method of measuring physical properties of the produced polyamide resin]

(1) Relative viscosity (R.V.)

After the monomer was extracted and removed, the prepared polyamide resin was dried, and 0.3 g of the sample was dissolved in 32.0 ml of 96% sulfuric acid. The dissolved solution was placed in a viscometer and allowed to stand in a constant temperature water bath at 25 ° C for 20 minutes. After the water drop was measured, the RV value was calculated by the following formula (1).

[Equation 1]

RV = Number of drops of sample / Number of drops of solvent

(2) Melting temperature (Tm)

10 mg of the prepared polyamide resin was placed in a sample holder, sealed, and then measured with a differential scanning calorimeter (DSC, manufactured by perkinelmer).

[Experimental Example: Production of polyamide resin]

(Example 1-1)

As shown in the following Table 1, 60 mol% of caprolactam was polymerized at 280 ° C. and 7 atm for 3 hours to prepare a polymer. The polymer thus prepared was mixed with 40 mol% of 2-pyrrolidone and heated at 200 ° C. and 7 atm for 3 hours Followed by polymerization to prepare a polyamide resin. At this time, water was used as a catalyst in 100 parts by mol based on 100 parts by mol of the monomer containing caprolactam and 2-pyrrolidone.

^{1 H-NMR (300㎒, TFA} -d 1): δ = 2.390 ~ 2.479 (5d, 2H), 2.882 ~ 2.937 (t, 2H), 3.814 ~ 3.863 (t, 2H)

(Examples 1-2 to 1-5)

In the same manner as in Example 1-1 except that the content of 2-pyrrolidone and caprolactam, the lactam polymerization step and the pyrrolidone polymerization step temperature in Example 1-1 were changed as shown in the following Table 1 To prepare a polyamide resin.

(Example 2-1)

40 mol% of 2-pyrrolidone was polymerized at 200 캜 and 7 atm for 3 hours to prepare a polymer. The polymer thus prepared was mixed with caprolactam in an amount of 60 mol% and polymerized at 280 캜 and 7 atm for 3 hours to obtain a polaramide resin . At this time, water was used as a catalyst in 100 parts by mol based on 100 parts by mol of the monomer containing caprolactam and 2-pyrrolidone.

(Examples 2-2 to 2-5)

In Example 2-1, the content of 2-pyrrolidone and caprolactam, the lactam polymerization step and the temperature of the pyrrolidone polymerization step were changed as in Examples 1-2 to 1-5, 2-1, a polyamide resin was prepared.

(Comparative Example 1)

30 mol% of 2-pyrrolidone and 70 mol% of caprolactam were mixed and polymerized at 250 캜 and 7 atm for 5 hours to prepare a polyamide resin. As the catalyst, water was used in an amount of 30 parts by mol per 100 parts by mol of the monomer containing caprolactam and 2-pyrrolidone.

(Comparative Examples 2 to 7)

Comparative Example 1 The procedure of Comparative Example 1 was repeated except that the content of 2-pyrrolidone and caprolactam and the content of the catalyst were changed as shown in Table 1 and the polymerization temperature was changed as shown in Table 1 To prepare a polyamide resin.

The relative viscosity and melting temperature of the polyamide resins prepared in Examples 1-1 to 1-5 and Comparative Examples 1 to 7 were measured, and the results are also shown in Table 1 below.

division The monomer (mol%) catalyst
(mol%) Temperature
(° C) Polymerization step
(step) Relative viscosity
(dl / g) Melting temperature
(° C) 2-pyrrolidone Caprolactam Example 1-1 40 60 100 280/200 2 2.09 190 Examples 1-2 40 60 100 280/190 2 2.19 189 Example 1-3 40 60 100 250/200 2 2.15 188 Examples 1-4 40 60 100 250/190 2 2.30 188 Examples 1-5 30 70 30 250/190 2 2.21 188 Comparative Example 1 30 70 30 250 One 1.79 197 Comparative Example 2 30 70 30 280 One 1.57 196 Comparative Example 3 30 70 30 300 One 1.55 196 Comparative Example 4 30 70 30 230 One 1.75 197 Comparative Example 5 40 60 100 250 One 1.50 189 Comparative Example 6 40 60 100 300 One 1.45 189 Comparative Example 7 40 60 100 210 One 1.38 190

Referring to Table 1, in Comparative Examples 1 to 4, in which the content of 2-pyrrolidone was 30 mol%, the relative viscosity was 1.90 or less, indicating that polyamide resin polymerization was not carried out, have.

In addition, in the case of Comparative Examples 5 to 7 in which the content of 2-pyrrolidone is 40 mol% or more, it can be seen that the polymerization of the polyamide resin is not achieved even when the content of the catalyst is 100 moles.

On the other hand, in the case of Examples 1-1 to 1-4, the polymerization of the polyamide resin proceeded to two different temperatures, and even when the content of 2-pyrrolidone was 40 mol%, the relative viscosity was 1.90 or more A polyamide resin can be produced. Further, referring to Examples 1-5, it is possible to prepare a polyamide resin having a 2-pyrrolidone content of 30 mol% even if the reaction of the polyamide resin is carried out in two stages, even if the catalyst content is reduced to 30 molar parts .

In addition, all of the polyamide resins produced in Examples 1-1 to 1-5 are found to have a melting temperature of 190 ° C or lower, which is below the pyrolysis temperature, so that pyrolysis of the polyamide resin does not occur during melt spinning.

Also in Examples 2-1 to 2-5, a polyamide resin having a relative viscosity of 1.90 or more was obtained, and it was confirmed that the melting temperature was all below the pyrolysis temperature.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (8)

A lactam polymerization step of polymerizing lactam having 5 to 7 carbon atoms at 250 to 280 캜 to prepare a polymer, and
And a pyrrolidone polymerization step of polymerizing the prepared polymer and 2-pyrrolidone at 130 to 200 DEG C to prepare a copolymer,
Wherein any one step selected from the group consisting of the lactam polymerization step, the pyrrolidone polymerization step and a combination thereof is a step of reacting water with 100 moles of the monomer containing 2-pyrrolidone and the lactam having 5 to 7 carbon atoms as a catalyst, 20 to 200 moles of the polyamide resin. The method according to claim 1,
Wherein the content of the 2-pyrrolidone in the polyamide resin is 30 mol% or more based on the total amount of the polyamide resin. The method according to claim 1,
Wherein the polyamide resin has a relative viscosity (RV) value of 1.9 or more. delete The method according to claim 1,
And discharging and chipping the produced copolymer at a temperature of 200 占 폚 or lower. A pyrrolidone polymerization step of polymerizing 2-pyrrolidone at 130 to 200 캜 to prepare a polymer, and
And a lactam polymerization step of polymerizing the prepared polymer and lactam having 5 to 7 carbon atoms at 250 to 280 ° C to prepare a copolymer,
Wherein any one step selected from the group consisting of the lactam polymerization step, the pyrrolidone polymerization step and a combination thereof is a step of reacting water with 100 moles of the monomer containing 2-pyrrolidone and the lactam having 5 to 7 carbon atoms as a catalyst, 20 to 200 moles of the polyamide resin. delete delete