Process for preparing polyamide by copolymerization of multiple components, polyamide prepared thereby, and composition comprising the same

Abstract

To provide a process for preparing a polyamide by copolymerization of multiple components, a polyamide prepared thereby, which exhibits excellent physical properties, and a composition including the same.SOLUTION: A copolymerized polyamide of the present invention is prepared by copolymerization of multiple components, and comprises (a) a first structural unit derived from lactam or α,ω-aminocarboxylic acid; (b) a second structural unit derived from aromatic diamine or aromatic dicarboxylic acid; and (c) a third structural unit derived from an aliphatic or cycloaliphatic diamine having 10 or more carbon atoms or an aliphatic or cycloaliphatic dicarboxylic acid having 10 or more carbon atoms, wherein the content of the first structural unit is 50 mol% to 96 mol%, and the total content of the second structural unit and the third structural unit is 4 mol% to 50 mol%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing polyamide by copolymerization, polyamide produced thereby, and a composition containing the same. Specifically, the present invention relates to a method for producing polyamide by copolymerization of a low molecular weight polyamide salt and lactam or α,ω-aminocarboxylic acid, polyamide produced thereby, and a composition containing the same.

Background Art

[0002] Polyamide refers to a polymer containing amide (-CO-NH-) units in the main chain. Polyamide can be produced from two different bifunctional monomer units each containing two identical reactive groups (e.g., -NH2 or -COOH), or from a single bifunctional monomer unit containing one amino group and one carboxyl group each, or from a single bifunctional monomer unit capable of forming these groups. For example, polyamide can be produced by a condensation polymerization reaction of diamine and dicarboxylic acid, a condensation polymerization reaction of aminocarboxylic acid, or a ring-opening polymerization reaction of lactam.

[0003] Polyamide is classified into aliphatic polyamide, aromatic polyamide, and alicyclic polyamide according to its molecular structure, and has excellent physical properties such as rigidity, friction resistance, abrasion resistance, oil resistance, and solvent resistance due to its molecular structure.

[0004] On the other hand, there have been attempts to blend two polyamides having different properties from each other to complement their respective physical properties. For example, in Korean Patent Publication No. 10-2012-0034742, two polyamides, PA MXD.10 and PA 6.10, were mixed in an extruder to produce a molded article having excellent elastic modulus. However, since the two polyamides are not chemically completely bonded, there are limitations in reducing the processing temperature and improving the low-temperature properties.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Korean Patent Publication No. 10-2012-0034742 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] An object of the present invention is to provide a method for producing polyamide by polycondensation, a copolymer polyamide produced thereby, which exhibits excellent physical properties, and a composition containing the same. [Means for Solving the Problems]

[0007] To achieve the above object, the present invention includes: (1) a step of producing a polyamide salt by condensation polymerization of a diamine and a dicarboxylic acid; and (2) a step of copolymerizing a lactam or an α,ω-aminocarboxylic acid with the polyamide salt, wherein the equivalent ratio of the dicarboxylic acid to the diamine is 1.05 to 1.0, and the molar ratio of the lactam or α,ω-aminocarboxylic acid to the repeating units derived from the diamine and dicarboxylic acid of the polyamide salt is 96:4 to 50:50, and provides a method for producing a copolymer polyamide.

[0008] In an embodiment of the present invention, in the above step (1), the dicarboxylic acid may include at least one of aliphatic dicarboxylic acids selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid; alicyclic dicarboxylic acids selected from the group consisting of cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid. Preferably, the dicarboxylic acid may be sebacic acid.

[0009] In an embodiment of the present invention, in the above step (1), the diamine may include at least one of aliphatic diamines selected from the group consisting of ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, 2-methyl-1,5-diaminopentane; alicyclic diamines selected from the group consisting of cyclohexanediamine, bis-(4-aminocyclohexyl)methane; and aromatic diamines such as xylylenediamine. Preferably, the diamine can be m-xylyenediamine.

[0010] In an embodiment of the present invention, the condensation polymerization in the above step (1) can be carried out at a temperature of 150 to 200 °C for 1 to 3 hours.

[0011] In an embodiment of the present invention, the polyamide salt obtained in the above step (I) may have a relative viscosity (sulfuric acid) of 1 to 2.

[0012] In an embodiment of the present invention, in the above step (2), the lactam may include at least one selected from the group consisting of laurolactam, caprolactam, piperidinone, pyrrolidone, enantholactam, capryllactam, propiolactam, valerolactam, heptanolactam, octanolactam, nonanolactam, decanolactam, undecanolactam, and dodecanolactam. Preferably, the lactam is caprolactam.

[0013] In an embodiment of the present invention, in the above step (2), the α,ω-aminocarboxylic acid may include at least one selected from the group consisting of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0014] In an embodiment of the present invention, the copolymerization in the above step (2) can be carried out in the presence of a phosphorus-based compound as a heat stabilizer and a catalyst. More specifically, the phosphorus-based compound can be a hypophosphorous acid compound or a phosphorous acid compound.

[0015] In an embodiment of the present invention, the copolymerization in the above step (2) may include a first copolymerization carried out at a pressure of 1 to 5 bar and a temperature of 250 to 300 °C for 1 to 3 hours, and a second copolymerization carried out at a pressure of 0.001 to 0.5 bar and a temperature of 200 to 300 °C for 0.1 to 12 hours.

[0016] In another embodiment of the present invention, there is provided a copolymer polyamide produced by the above manufacturing method and comprising: (a) a first structural unit derived from a lactam or an α,ω-aminocarboxylic acid; (b) a second structural unit derived from an aromatic diamine or an aromatic dicarboxylic acid; and (c) a third structural unit derived from an aliphatic or alicyclic diamine having 10 or more carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms, wherein the content of the first structural unit is 50 to 96 mol%, and the total content of the second structural unit and the third structural unit is 4 to 50 mol%.

[0017] In an embodiment of the present invention, the copolymer polyamide may further comprise (d) a fourth structural unit derived from an aliphatic or alicyclic diamine having 2 to 9 carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 2 to 9 carbon atoms.

[0018] In an embodiment of the present invention, the copolymer polyamide may have a relative viscosity (sulfuric acid) of 2.0 to 5.0.

[0019] In still another embodiment of the present invention, there is provided a copolymer polyamide composition comprising: (A) 4 to 50% by weight of the copolymer polyamide according to the embodiment of the present invention; (B) 50 to 96% by weight of a homopolyamide produced from a lactam or an α,ω-aminocarboxylic acid; and (C) 0 to 20% by weight of an impact reinforcing agent.

[0020] In an embodiment of the present invention, as the impact reinforcing agent (C), it may include at least one selected from the group consisting of ethylene-propylene rubber grafted with maleic anhydride, ethylene-1-butene rubber, ethylene-butylene rubber, ethylene-1-pentene rubber, ethylene-1-hexene rubber, ethylene-1-heptene rubber, ethylene-1-octene rubber, and ethylene-4-methyl-1-pentene rubber. Preferably, the impact reinforcing agent (C) is ethylene-butylene rubber grafted with maleic anhydride.

[0021] In an embodiment of the present invention, the polyamide composition may further contain an additive (D) in a content of 3 parts by weight or less based on 100 parts by weight of components (A) to (C).

[0022] At this time, the additive (D) may contain at least one selected from the group consisting of an antioxidant, a heat stabilizer, a neutralizing agent, a weather stabilizer, an antistatic agent, a lubricant, a slip agent, a pigment, and a dye.

[0023] In a specific embodiment, the additive (D) may contain a primary antioxidant selected from phenolic antioxidants, BHT (butylated Hydroxytoluene), Irganox 1098, Irganox 1076, Irganox 1010, and Irganox 3114, a secondary antioxidant which is Irgafos 168, and a heat stabilizer which is sodium hypophosphite (NaH2PO2).

[0024] In still another embodiment of the present invention, there is provided a molded article of the copolymer polyamide or the copolymer polyamide composition produced by molding the copolymer polyamide.

[0025] In an embodiment of the present invention, the molded article of the copolymer polyamide can be used for automotive parts, environmental materials, tank liners, containers, building materials, electrical and electronic parts, space / aerospace, dorrons, food and functional packaging, housings, and energy materials.

Advantages of the Invention

[0026] The copolymer polyamide and the composition containing the same according to the embodiments of the present invention can exhibit excellent mechanical properties, low-temperature properties, and gas barrier properties.

Modes for Carrying Out the Invention

[0027] Hereinafter, the present invention will be described in more detail.

[0028] Method for Producing Copolymer Polyamide The method for producing a copolymer polyamide according to an embodiment of the present invention includes: (1) a step of producing a polyamide salt by condensation polymerization of a diamine and a dicarboxylic acid; and (2) a step of copolymerizing a lactam or an α,ω-aminocarboxylic acid with the polyamide salt, wherein the equivalent ratio of the dicarboxylic acid to the diamine is 1.05 to 1.0, and the molar ratio of the lactam or α,ω-aminocarboxylic acid to the repeating units derived from the diamine and dicarboxylic acid of the polyamide salt is 96:4 to 50:50, and a method for producing a copolymer polyamide is provided.

[0029] Step (1) In the above step (1), a polyamide salt is produced by condensation polymerization of a diamine and a dicarboxylic acid.

[0030] First, the dicarboxylic acid, which is one of the monomers for producing the polyamide salt, is filled into the reactor in a solid state and then melted, or is previously melted in a separate melting tank and then a predetermined amount is filled into the reactor.

[0031] Here, the reactor used for producing the polyamide salt is not particularly limited, but may be a stirred tank-reactor equipped with a stirrer. Here, the type of the stirrer is not particularly limited as long as it can sufficiently stir the reaction mixture of the diamine and the dicarboxylic acid. In one embodiment of the present invention, the stirrer may be of a helical ribbon type or an anchor type.

[0032] In an embodiment of the present invention, examples of the dicarboxylic acid used in the production of the polyamide salt include aliphatic dicarboxylic acids selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid; alicyclic dicarboxylic acids selected from the group consisting of cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid, but are not particularly limited thereto. Preferably, the dicarboxylic acid is sebacic acid.

[0033] While stirring the molten dicarboxylic acid in the reactor with a stirrer, an inert gas such as nitrogen is supplied through a purge line to sufficiently purge the inside of the reactor.

[0034] Thereafter, the temperature inside the reactor is heated to a temperature of 150 to 200 °C at which the amidation reaction is substantially carried out. Specifically, the temperature inside the reactor is set so that the polyamide salt, which is the product during the addition of diamine, is maintained in a molten state to ensure uniform fluidity throughout the reaction system.

[0035] Next, diamine, which is the other monomer for the production of the polyamide salt, is continuously or intermittently added into the reactor. At this time, the diamine flows into the reactor from the diamine supply tank using a metering pump. Here, the specific types and configurations of the diamine supply tank and the metering pump are not particularly limited as long as they can quantitatively supply the diamine to the reactor.

[0036] In an embodiment of the present invention, examples of diamines used in the production of polyamide salts include aliphatic diamines selected from the group consisting of ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, and 2-methyl-1,5-diaminopentane; alicyclic diamines selected from the group consisting of cyclohexanediamine and bis-(4-aminocyclohexyl)methane; and aromatic diamines such as xylylenediamine, but are not particularly limited thereto. Preferably, the diamine is m-xylyenediamine.

[0037] The diamine is preferably added over 0.5 to 4 hours so that the reaction proceeds gradually while maintaining the reaction mixture in a molten state.

[0038] In an embodiment of the present invention, in the above step (1), the equivalent ratio of dicarboxylic acid to diamine is 1.05 to 1.0. When the equivalent ratio of dicarboxylic acid to diamine is within the above range, condensation polymerization can be appropriately carried out.

[0039] It is preferable to adjust the temperature in the reactor so that the temperature in the reactor becomes 150 to 250 °C when all of the diamine has been added. At this time, since the rate of temperature increase in the reactor is determined by the heat of amidation reaction, the latent heat of vaporization of condensed water, the supplied heat amount, etc., the addition rate of the diamine is preferably adjusted so that the temperature in the reactor falls within the above range when all of the diamine has been added.

[0040] In an embodiment of the present invention, the condensation polymerization in the above step (1) can be carried out at a temperature of 150 to 250 °C for 1 to 3 hours.

[0041] In an embodiment of the present invention, the polyamide salt obtained in the above step (1) may have a relative viscosity (sulfuric acid) of 1 to 2. When the relative viscosity of the polyamide salt is within the above range, copolymerization can be appropriately carried out in step (2).

[0042] The polyamide salt obtained in the above step (1) can be thoroughly washed using an ethanol solvent to remove unreacted monomers, filtered using filter paper or a filter mesh, and then dried in a vacuum oven at about 50°C.

[0043] Step (2) In the above step (2), lactam or α,ω-aminocarboxylic acid is copolymerized with the polyamide salt to produce a copolymerized polyamide.

[0044] The polyamide salt produced in step (1) is charged into a reactor together with a lactam or α,ω-aminocarboxylic acid monomer and optionally a phosphorus-based compound which is a heat stabilizer and a catalyst.

[0045] The copolymerization in step (2) can be carried out in the reactor used in step (1) or in a separate reactor.

[0046] In an embodiment of the present invention, the lactam used in the production of the copolyamide can be a lactam having 3 to 20 carbon atoms. Examples of such lactams include laurolactam, caprolactam, piperidinone, pyrrolidone, enantholactam, capryllactam, propiolactam, valerolactam, heptanolactam, octanolactam, nonanolactam, decanolactam, undecanolactam, and dodecanolactam, but are not particularly limited thereto. Preferably, the lactam is caprolactam.

[0047] In an embodiment of the present invention, an α,ω-aminocarboxylic acid can be used instead of the lactam in the production of the copolyamide. At this time, examples of the α,ω-aminocarboxylic acid include aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, but are not particularly limited thereto.

[0048] In an embodiment of the present invention, in the above step (2), the molar ratio of the lactam or α,ω-aminocarboxylic acid to the repeating units derived from the diamine and dicarboxylic acid of the polyamide salt is 96:4 to 50:50. When the molar ratio of the lactam or α,ω-aminocarboxylic acid to the repeating units derived from the diamine and dicarboxylic acid of the polyamide salt is within the above range, the copolyamide can exhibit excellent physical properties.

[0049] In an embodiment of the present invention, the copolymerization in the above step (2) can be carried out in the presence of a phosphorus-based compound as a heat stabilizer and a catalyst. Here, the phosphorus-based compound serves as a heat stabilizer to prevent discoloration of the copolymerized polyamide produced, while also serving as a catalyst to increase the degree of polymerization of the copolymerized polyamide produced.

[0050] The phosphorus-based compound can be a hypophosphorous acid compound (also referred to as a phosphinic acid compound or a phosphonous acid compound) or a phosphorous acid compound (also referred to as a phosphonic acid compound), but is not particularly limited thereto. The phosphorus-based compound can be a metal salt or an alkali metal salt.

[0051] Examples of the hypophosphorous acid compound include hypophosphorous acid; metal hypophosphites such as sodium hypophosphite, potassium hypophosphite, and lithium hypophosphite; hypophosphorous acid compounds such as ethyl hypophosphite, dimethylphosphinic acid, phenylmethylphosphinic acid, phenylphosphonous acid, and ethyl phenylphosphonite; and metal phenylphosphonites such as sodium phenylphosphonite, potassium phenylphosphonite, and lithium phenylphosphonite.

[0052] Specific examples of the phosphorous acid compound include phosphorous acid and pyrophosphorous acid; metal phosphites such as sodium hydrogen phosphite and sodium phosphite; phosphorous acid compounds such as triethyl phosphite, triphenyl phosphite, ethylphosphonic acid, phenylphosphonic acid, and diethyl phenylphosphonate; and metal phenylphosphonates such as sodium ethylphosphonate, potassium ethylphosphonate, sodium phenylphosphonate, potassium phenylphosphonate, and lithium phenylphosphonate.

[0053] Preferably, the phosphorus-based compound is sodium hypophosphite (NaH2PO2).

[0054] The content of the phosphorus-based compound is 0.3 to 1.0% by weight, preferably 0.5 to 0.7% by weight, based on the total weight of the theoretical polymer obtained after polymerization.

[0055] After filling the reactor with all the raw materials for copolymerization, an inert gas such as nitrogen is supplied through the purge line to thoroughly purge the inside of the reactor.

[0056] In an embodiment of the present invention, the copolymerization in the above step (2) may include a primary copolymerization and a secondary copolymerization.

[0057] Here, the primary copolymerization is a step in which condensation polymerization is carried out in a state where the reactants are melted to obtain a low-viscosity polyamide.

[0058] Specifically, the primary copolymerization can be carried out at a pressure of 1 to 5 bar and a temperature of 250 to 300 °C for 1 to 3 hours.

[0059] The secondary copolymerization is a step in which the low-viscosity polyamide is polymerized in a molten state or a solid state under reduced pressure conditions to obtain a higher-viscosity polyamide.

[0060] Specifically, the secondary copolymerization can be carried out at a pressure of 0.001 to 0.5 bar and a temperature of 200 to 300 °C for 0.1 to 12 hours.

[0061] Copolymerized polyamide The copolymerized polyamide according to the embodiment of the present invention is produced by the above production method and includes (a) a first structural unit derived from lactam or α,ω-aminocarboxylic acid; (b) a second structural unit derived from an aromatic diamine or an aromatic dicarboxylic acid; and (c) a third structural unit derived from an aliphatic or alicyclic diamine having 10 or more carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms. The content of the first structural unit is 50 to 96 mol%, and the total content of the second structural unit and the third structural unit is 4 to 50 mol%.

[0062] In an embodiment of the present invention, since the copolyamide is produced by the production method according to the embodiment of the present invention, it may contain all of the structural units formed by the condensation polymerization of diamine and dicarboxylic acid in step (1) of the production method according to the embodiment of the present invention, and the structural units formed by the polymerization of lactam or α,ω-aminocarboxylic acid in step (2).

[0063] Specifically, the first structural unit of the copolyamide is derived from lactam or α,ω-aminocarboxylic acid. Here, lactam and α,ω-aminocarboxylic acid are as described in the item of the production method of the copolyamide.

[0064] In the copolyamide, the content of the first structural unit is 50 to 96 mol%. When the content of the first structural unit is within the above range, the copolyamide can exhibit excellent physical properties.

[0065] In addition, the second structural unit of the copolyamide is derived from an aromatic diamine or an aromatic dicarboxylic acid. Here, the aromatic diamine and the aromatic dicarboxylic acid are as described in the item of the production method of the copolyamide. Specifically, the aromatic diamine can include xylylenediamine, and the aromatic dicarboxylic acid can include phthalic acid, isophthalic acid, terephthalic acid, or naphthalenedicarboxylic acid.

[0066] In addition, the third structural unit of the copolyamide is derived from an aliphatic or alicyclic diamine having 10 or more carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms. Here, the aliphatic or alicyclic diamine having 10 or more carbon atoms and the aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms are as described in the item of the production method of the copolyamide.

[0067] Specifically, the aliphatic or alicyclic diamine having 10 or more carbon atoms may include 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, 2-methyl-1,5-diaminopentane or bis-(4-aminocyclohexyl)methane, and the aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms may include sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid or octadecanedioic acid.

[0068] In the copolymer polyamide, the total content of the second structural unit and the third structural unit is 4 to 50 mol%. When the total content of the second structural unit and the third structural unit is within the above range, the copolymer polyamide can exhibit excellent physical properties.

[0069] In an embodiment of the present invention, the copolymer polyamide may further include a fourth structural unit derived from an aliphatic or alicyclic diamine having 2 to 9 carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 2 to 9 carbon atoms. Here, the aliphatic or alicyclic diamine having 2 to 9 carbon atoms and the aliphatic or alicyclic dicarboxylic acid having 2 to 9 carbon atoms are as described in the item of the method for producing the copolymer polyamide.

[0070] Specifically, the aliphatic or alicyclic diamine having 2 to 9 carbon atoms may include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane or cyclohexanediamine, and the aliphatic or alicyclic dicarboxylic acid having 2 to 9 carbon atoms may include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid or cyclohexanedicarboxylic acid.

[0071] The content of the fourth structural unit in the copolyamide can be 20 mol% or less.

[0072] In an embodiment of the present invention, the copolyamide can have a relative viscosity (sulfuric acid) of 2.0 to 5.0. When the relative viscosity of the copolyamide is within the above range, excellent physical properties can be exhibited.

[0073] Copolyamide composition The copolyamide composition according to an embodiment of the present invention comprises (A) 4 to 50% by weight of the copolyamide according to an embodiment of the present invention; (B) 50 to 96% by weight of a homopolyamide produced from lactam or α,ω-aminocarboxylic acid; and (C) 0 to 20% by weight of an impact reinforcing agent.

[0074] The copolyamide composition according to an embodiment of the present invention contains the copolyamide (A) according to an embodiment of the present invention. Here, the copolyamide (A) is as described in the item of the copolyamide above.

[0075] The content of the copolyamide (A) in the copolyamide composition is 4 to 50% by weight. When the content of the copolyamide (A) is within the above range, the composition can exhibit excellent physical properties.

[0076] The copolyamide composition according to an embodiment of the present invention contains a homopolyamide (B) produced from lactam or α,ω-aminocarboxylic acid. Here, the type and production method of the homopolyamide (B) are not particularly limited as long as it is produced from lactam or α,ω-aminocarboxylic acid. Lactam and α,ω-aminocarboxylic acid are as described in the item of the production method of the copolyamide above.

[0077] The content of the homopolyamide (B) in the copolyamide composition is 50 to 96% by weight. When the content of the homopolyamide (B) is within the above range, the composition can exhibit excellent physical properties.

[0078] In addition, the copolymer polyamide composition according to the embodiment of the present invention may contain an impact reinforcing agent (C).

[0079] In an embodiment of the present invention, the impact reinforcing agent (C) can be a thermoplastic elastomer grafted with maleic anhydride. More specifically, the impact reinforcing agent (C) can contain at least one selected from the group consisting of ethylene-propylene rubber, ethylene-1-butene rubber, ethylene-butylene rubber, ethylene-1-pentene rubber, ethylene-1-hexene rubber, ethylene-1-heptene rubber, ethylene-1-octene rubber, and ethylene-4-methyl-1-pentene rubber grafted with maleic anhydride. Preferably, the impact reinforcing agent (C) is ethylene-butylene rubber grafted with maleic anhydride.

[0080] The content of maleic anhydride in the thermoplastic elastomer grafted with maleic anhydride can be 0.1 to 1% by weight.

[0081] The content of the impact reinforcing agent (C) in the copolymer polyamide composition is 0 to 20% by weight.

[0082] In an embodiment of the present invention, the copolymer polyamide composition may further contain an additive (D) in a content of 3 parts by weight or less based on 100 parts by weight of components (A) to (C). At this time, the additive (D) can contain at least one selected from the group consisting of an antioxidant, a heat resistance stabilizer, a neutralizing agent, a weather resistance stabilizer, an antistatic agent, a lubricant, a slip agent, a pigment, and a dye.

[0083] In an exemplary embodiment, the additive (D) can contain at least one antioxidant selected from phenol-based antioxidants such as Irganox 1098, Irganox 1076, Irganox 1010, Irganox 3114, which are primary antioxidants that remove radicals and improve processing heat stability, BHT (butylated Hydroxytoluene), and Irgafos 168, which is a phosphite-based antioxidant as a secondary antioxidant that decomposes peroxides generated by the primary antioxidant.

[0084] In an exemplary embodiment, the additive (D) may include sodium hypophosphite (NaH2PO2), which is a phosphorus-based heat stabilizer.

[0085] The method for producing the copolymer polyamide composition according to the embodiment of the present invention is not particularly limited, and the method for producing a polyamide composition known in the technical field to which the present invention belongs can be used as it is or appropriately modified. The above-described resin components and compounds can be freely selected and mixed in a desired order without any particular order restriction.

[0086] Specifically, for example, each of the above-described resins and additives can be melted and extruded at a temperature of 160 to 230°C using a single-screw / twin-screw extruder in a required amount to produce a copolymer polyamide composition in pellet form.

[0087] Further, according to still another embodiment of the present invention, there is provided a molded article of a copolymer polyamide produced by molding the copolymer polyamide or copolymer polyamide composition of the present invention.

[0088] The method for producing a molded article from the copolymer polyamide or copolymer polyamide composition according to the embodiment of the present invention is not particularly limited, and a method known in the technical field to which the present invention belongs can be used. For example, a molded article of a copolymer polyamide can be produced by molding the copolymer polyamide or copolymer polyamide composition according to the embodiment of the present invention by ordinary methods such as injection molding, extrusion molding, cast molding, blow molding, rotational molding, and film molding.

[0089] The molded article of the copolymer polyamide according to the embodiment of the present invention exhibits excellent mechanical properties, low-temperature properties, and gas barrier properties. Therefore, the molded article of the copolymer polyamide can be usefully used for automotive parts, environmental materials, tank liners such as hydrogen tank liners, containers, building materials, electric and electronic parts, space / aerospace, dron, food and functional packaging, housings, and energy materials (batteries, wind / solar power generation).

Examples

[0090] Example 1-1 A reactor equipped with a stirrer was charged with 340 g of sebacic acid, heated to 150 °C while purging the inside of the reactor with nitrogen to melt the sebacic acid. While stirring the molten sebacic acid and distilling off the vaporizing components, 204 g of m-xylylenediamine (m-XDA) was added dropwise over 2 hours using a dropping funnel, and the reaction mixture was stirred for 1 hour to cause a reaction. The reaction product was washed with 2 liters of ethanol, filtered, and then dried to obtain a polyamide salt. The relative viscosity (sulfuric acid) of the obtained polyamide salt was 1.5.

[0091] 160 g of the polyamide salt obtained above, 1,440 g of caprolactam, and 12.43 g of sodium hypophosphite (NaH2PO2) were placed in a reactor equipped with a stirrer, and the reaction mixture was melted by heating at 240 °C while purging the inside of the reactor with nitrogen.

[0092] While maintaining the pressure in the reactor at 4 bar or less, the reaction mixture was heated at 260 °C while stirring at a speed of 10 rpm or more and reacted for 3 hours. Next, while maintaining the pressure in the reactor at 0.01 bar using a vacuum pump, the reaction mixture was reacted at 260 °C for 1 hour. After completion of the reaction, the inside of the reactor was purged with nitrogen and cooled to obtain a copolymer polyamide. The relative viscosity (sulfuric acid) of the obtained copolymer polyamide was 3.7.

[0093] Example 1-2 A copolymer polyamide was obtained in the same manner as in Example 1-1, except that 1,181 g of the polyamide salt obtained in Example 1-1 and 418 g of caprolactam were used. The relative viscosity (sulfuric acid) of the obtained copolymer polyamide was 4.0.

[0094] Comparative Example 1-1 The flask was maintained at 70 °C under vacuum to remove the moisture inside the flask. After releasing the vacuum of the flask, 500 g of caprolactam (CL), 0.318 g of sodium hydride (NaH), and 18.85 g of ethylene bis-stearamide were added, and the temperature was raised to 165 °C under vacuum. The reaction temperature was set to 240 °C, and while introducing nitrogen gas, the hydrogen gas generated as the raw materials melted was removed. 2.30 g of toluene diisocyanate (TDI) was injected and reacted for 20 minutes. After 20 minutes elapsed, 50 ml of an aqueous formic acid solution (formic acid: distilled water = 1:1, v / v) was added to the flask to terminate the reaction, and 485 g of the polymerized polyamide was obtained. The relative viscosity (sulfuric acid) of the obtained polyamide was 2.9.

[0095] Test Example The physical properties of the polyamide resins obtained in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 1.

[0096] The relative viscosity of each polyamide resin or composition was measured at 25 °C using a UVS basic apparatus manufactured by UFIT AG. Specifically, 1 g of the resin or composition was dissolved in 100 ml of 96% H₂SO₄. The dropping time in a certain section inside the viscometer was measured. After measuring the dropping time t₀ of the H₂SO₄ reference solution and the dropping time t of each sample, t / t₀ was determined as the relative viscosity (RV) of the resin.

[0097] Also, each polyamide resin or composition was injection-molded to produce test pieces, and the tensile properties were measured by the method of ISO 527, and the impact properties were measured by the method of ISO 179 / 1eA.

[0098]

Table 1

[0099] Example 2-1 10 g of the copolymer polyamide obtained in Example 1-1, 72.5 g of a polyamide (PA6, relative viscosity 2.9) produced from caprolactam, and 17.5 g of an ethylene-butylene rubber grafted with maleic anhydride (Mitsubishi Chemical, MH5020C) were added with 0.1 g of Irganox 1098 as a primary antioxidant, 0.5 g of Irgafos 168 as a secondary antioxidant, and 0.25 g of a phosphorus-based heat stabilizer (NaH2PO2). After that, the mixture was extruded at 250 °C using an extruder to produce a copolymer polyamide composition.

[0100] Example 2-2 A copolymer polyamide composition was produced in the same manner as in Example 2-1, except that the copolymer polyamide obtained in Example 1-2 and the polyamide produced from caprolactam were used.

[0101] The physical properties of the copolymer polyamide composition obtained in the above examples were measured by the above method, and the results are shown in Table 2.

[0102]

Table 2

Industrial Applicability

[0103] As confirmed from Table 1 and Table 2 above, the copolymer polyamide according to the embodiments of the present invention and the composition containing the same are excellent in mechanical properties such as tensile properties and impact resistance properties.

Claims

1. (1) A step of producing a polyamide salt by condensation polymerization of a diamine and a dicarboxylic acid; and (2) a step of copolymerizing a lactam or an α,ω-aminocarboxylic acid with the polyamide salt, wherein the equivalent ratio of the dicarboxylic acid to the diamine is 1.05 to 1.0, and the molar ratio of the lactam or α,ω-aminocarboxylic acid to the repeating units derived from the diamine and dicarboxylic acid of the polyamide salt is 96:4 to 50:

50. A method for producing a copolymerized polyamide.

2. In the above step (1), the dicarboxylic acid is at least one of aliphatic dicarboxylic acids selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid; alicyclic dicarboxylic acids selected from the group consisting of cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid. The method for producing a copolymerized polyamide according to Claim 1.

3. In the above step (1), the diamine is at least one of aliphatic diamines selected from the group consisting of ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, 2-methyl-1,5-diaminopentane; alicyclic diamines selected from the group consisting of cyclohexanediamine, bis-(4-aminocyclohexyl)methane; and aromatic diamines which are xylylenediamine. The method for producing a copolymerized polyamide according to Claim 1.

4. The method for producing a copolymer polyamide according to claim 1, wherein in the above step (1), the dicarboxylic acid is sebacic acid and the diamine is m-xylylenediamine.

5. The method for producing a copolymer polyamide according to claim 1, wherein the condensation polymerization in the above step (1) is carried out at a temperature of 160 to 250 ° C for 1 to 3 hours.

6. The method for producing a copolymer polyamide according to claim 1, wherein the polyamide salt obtained in the above step (1) has a relative viscosity (sulfuric acid) of 1 to 2.

7. The method for producing a copolymer polyamide according to claim 1, wherein in the above step (2), the lactam contains at least one selected from the group consisting of laurolactam, caprolactam, piperidione, pyrrolidone, enantholactam, capryllactam, propiolactam, valerolactam, heptanolactam, octanolactam, nonanolactam, decanolactam, undecanolactam and dodecanolactam.

8. The method for producing a copolymer polyamide according to claim 1, wherein in the above step (2), the α,ω-aminocarboxylic acid contains at least one selected from the group consisting of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid.

9. The method for producing a copolymer polyamide according to claim 1, wherein the copolymerization in the above step (2) is carried out in the presence of a phosphorus-based compound as a heat stabilizer and a catalyst.

10. The method for producing a copolymer polyamide according to claim 9, wherein the phosphorus-based compound is a hypophosphorous acid compound or a phosphorous acid compound.

11. The method for producing a copolymer polyamide according to claim 1, wherein the copolymerization in step (2) includes a first copolymerization carried out at a pressure of 1 to 5 bar and a temperature of 250 to 300 ° C for 1 to 3 hours, and a second copolymerization carried out at a pressure of 0.001 to 0.5 bar and a temperature of 200 to 300 ° C for 0.1 to 12 hours.

12. A copolymer polyamide produced by the production method according to any one of claims 1 to 11, comprising: (a) a first structural unit derived from a lactam or an α,ω-aminocarboxylic acid; (b) a second structural unit derived from an aromatic diamine or an aromatic dicarboxylic acid; and (c) a third structural unit derived from an aliphatic or alicyclic diamine having 10 or more carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 10 or more carbon atoms, wherein the content of the first structural unit is 50 to 96 mol%, and the total content of the second structural unit and the third structural unit is 4 to 50 mol%.

13.

14. The copolymer polyamide according to claim 12, further comprising (d) a fourth structural unit derived from an aliphatic or alicyclic diamine having 2 to 9 carbon atoms or an aliphatic or alicyclic dicarboxylic acid having 2 to 9 carbon atoms.

15. The copolymer polyamide according to claim 12, having a relative viscosity (sulfuric acid) of 2.0 to 5.

0.

16. A copolymer polyamide composition comprising: (A) 4 to 50% by weight of the copolymer polyamide according to claim 12; (B) 50 to 96% by weight of a homopolyamide produced from a lactam or an α,ω-aminocarboxylic acid; and (C) 0 to 20% by weight of an impact reinforcing agent.

17. The copolymer polyamide composition according to claim 15, wherein the impact reinforcing agent (C) comprises at least one selected from the group consisting of ethylene-propylene rubber, ethylene-1-butene rubber, ethylene-butylene rubber, ethylene-1-pentene rubber, ethylene-1-hexene rubber, ethylene-1-heptene rubber, ethylene-1-octene rubber, and ethylene-4-methyl-1-pentene rubber grafted with maleic anhydride.

18. The copolymer polyamide composition according to claim 15, further comprising an additive (D) in a content of 3 parts by weight or less based on 100 parts by weight of components (A) to (C).

19.

20. Additive (D) is a phenolic antioxidant, a primary antioxidant selected from butylated hydroxytoluene (BHT), Irganox 1098, Irganox 1076, Irganox 1010, and Irganox 3114, a secondary antioxidant which is Irgafos 168, and a heat stabilizer which is sodium hypophosphite (NaH ２ PO ２ ), the copolymer polyamide composition according to claim 18. A molded article of the copolymer polyamide, produced by molding the copolymer polyamide according to claim 12 or the copolymer polyamide composition according to claim 15.

21. ​ The molded article of the copolymer polyamide according to claim 20, which is for automotive parts, environmental materials, tank liners, containers, building materials, electrical and electronic parts, space and aviation, drones, food and functional packaging, housings, and energy materials.

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