KR100496381B1 - Copolyamide Resin Composition Containing Monmorillonite - Google Patents

Abstract

The present invention relates to a composition of a polyamide resin containing montmorillonite, wherein the equivalent mixture of m -xylenediamine and adipic acid constituting MXD-6 nylon is 100 to 70% by weight, and can form polyamide in addition to the above monomers. 0.5 to 10 parts by weight of montmorillonite is added to 100 parts by weight of a polyamide polymer having 0 to 30% by weight of the monomer present, and is copolymerized. It was possible to obtain a resin composition of copolymerized polyamide that was excellent in this and particularly excellent in elongation at low temperatures.

Description

Copolyamide Resin Composition Containing Monmorillonite

The present invention relates to a composition of a polyamide resin comprising montmorillonite having a structure of laminated silicates, and more particularly to a copolymerized polyamide resin composition from a mixture of monomers and montmorillonite capable of forming a polyamide.

Polyamide, which has excellent advantages such as mechanical strength, chemical resistance, and gas barrier property, is a representative engineering plastic that is widely used as a material for automobile parts, electronic products, and food packaging. Recently, montmorillonite has been attempted to further improve these properties and to impart properties such as hygroscopicity, dimensional stability, and flame retardancy to polyamides. The layered silicate structure of montmorillonite has an aspect ratio of about 300 to 1,000 times and has a dimension of nanometer in the thickness direction, resulting in uniform dispersion in the polyamide resin. In this case, it provides a way to achieve great improvements in physical properties.

U.S. Patent No. 5,248,720 requires a process to increase the interlaminar distance of montmorillonite using a swelling agent in order to uniformly disperse montmorillonite in the polyamide resin. It has the disadvantage of increasing transparency and low stretchability.

US Patent No. 5,741,601 to improve this problem provides a method for producing a nanocomposite in which fluoromica is uniformly dispersed in a polyamide resin without any additional pretreatment by using fluoro mica with high swellability. However, although the above method provides a relatively simple manufacturing process, the prepared nanocomposite exhibits a property of decreasing elongation and transparency, and thus a process for increasing elongation in a film processing process is required.

An object of the present invention is to overcome the above problems, by preparing a nanocomposite of montmorillonite-containing copolymer polyamide resin from a mixture of monomers and montmorillonite, excellent dispersibility, excellent gas barrier properties, transparency and especially at low temperatures It relates to a resin composition of copolymerized polyamide having excellent stretchability.

That is, a method of preparing a nanocomposite having homogeneous dispersibility by copolymerizing monomers capable of forming polyamide with montmorillonite and copolymerizing polyamide forming a matrix to improve transparency and stretchability of the matrix resin It is to obtain a copolymerized polyamide resin composition in which the prepared nanocomposite exhibits excellent gas barrier properties.

The polyamide resin of the present invention is m -xylenediamine constituting the MXD-6 nylon, MXD-6 nylon consisting of 100 to 70% by weight of adipic acid and other monomers capable of forming polyamide 0 to 30% by weight Or it is composed of 100 parts by weight of polyamide copolymer and 0.5 to 10 parts by weight of montmorillonite, and excellent dispersibility of montmorillonite in the polyamide resin thus prepared, and excellent gas barrier property, transparency, elongation at low temperature.

Hereinafter, the present invention will be described in detail.

In the copolyamide, m -xylenediamine and adipic acid, which constitute MXD-6 nylon, are 100 to 70% by weight based on the raw materials introduced. The two raw materials used are 1: 1 equivalents. Other monomers capable of forming polyamides include ε-caprolactam, tetramethylenediamine, hexamethylenediamine, terephthalic acid, isophthalic acid and 12-aminododecanoic acid. It comprises by weight and consists of 0.5 to 10 parts by weight of montmorillonite with respect to 100 parts by weight of polyamide copolymer.

Conventional montmorillonite-containing polyamide nanocomposites have improved the physical properties of nylon 6 as a matrix resin by enhancing mechanical properties, enhancing heat resistance, and increasing gas barrier properties. However, the nanocomposite of nylon 6 exhibits an increase in crystallization rate as montmorillonite acts as a nucleating agent to promote crystallization of the resin.

In the injection processing, the increase of the crystallization speed mainly plays a role in improving workability and dimensional stability, but in the extrusion stretching process, problems such as a decrease in transparency and an increase in stretching stress are caused. In US Pat. No. 5,741,601, nanocomposites using fluoromicas may be prepared by impregnating water in a fabric in the process of stretching to a film to improve stretchability or to perform stretching on one axis and later on another axis. Film processing is performed. However, the film thus produced has a disadvantage in that the transparency decreases and the Haze increases.

In order to solve this processing problem, the present invention intends to transform the matrix resin constituting the nanocomposite into copolymer polyamide. The m -xylenediamine which is a monomer which comprises a copolymer polyamide contains the phenylene structure, and has the characteristic that the substitution position of a phenylene structure is in a meta position. Due to this structure, MXD-6 nylon, which m -xylenediamine is formed by the reaction with adipic acid, has a rigid property and a slow crystallization rate, and thus has transparency and excellent stretchability in molding. In addition to these processing advantages, MXD-6 nylon is used for packaging films because of its excellent barrier property against oxygen and humidity.

When the amount of the mixture of m -xylenediamine and adipic acid forming MXD-6 nylon in the copolymerized polyamide resin is less than 70% by weight of the raw material forming the total polyamide, the properties of the MXD-6 nylon are reduced and copolymerization is performed. Due to the low solidification rate of polyamide, the workability is poor during polymerization or processing, and the degree of crystallinity is too small, making it difficult to obtain desired properties such as gas barrier properties.

The montmorillonite used in the present invention has an appearance ratio (length / diameter ratio) of more than 300 times and is very large, and also has a strong binding force with the polyamide resin, and thus it is advantageous to obtain the desired effect of the present invention. It is used in the quantity of 0.5-10 weight part with respect to a part. If it is less than 0.5 parts by weight it is difficult to obtain the desired effect of the present invention, if it exceeds 10 parts by weight montmorillonite having a large value of the appearance ratio increases the melt viscosity of the polymer there is a difficulty in polymerization and processing.

The montmorillonite used in the present invention is a structure in which platelets having an interlaminar distance of 10 Å are laminated or montmorillonite treated by expanding the distance between the plates to reduce its swelling property. As a treatment agent used to increase the distance between the plates, ε-caprolactam, 12-aminododecanoic acid, octadecylamine, tallow ammonium ion, and the like may be used.

The relative viscosity of the polyamide resin used in the present invention is preferably in the range of 1.5 to 3.5. If the relative viscosity is less than 1.5, the mechanical properties of the resin composition are lowered, so that it is difficult to obtain desired properties. If the relative viscosity is more than 3.5, the processability of the resin composition is poor.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the present invention is not limited to the Examples.

(Example 1)

Into a 40L reactor, 1.0 kg of ε-caprolactam, 4.34 kg and 4.66 kg of m -xylenediamine and adipic acid were added, and 300 g of montmorillonite (Closis 15A of Southern Clay Products, 125 meq / 100 g) and 2.0 kg of water were added. The mixture was stirred and the temperature was raised to 250 ° C. to maintain 14 kg / cm ² and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² to prepare a chip, which was washed with water at 95 ° C. for 12 hours to remove unreacted material, and then vacuum dried at 100 ° C.

Thermal analysis of the dried chip was analyzed using a differential thermal analyzer (DSC) and extruded using a melt extruder at a temperature of 250 ℃ to prepare a sheet of 150㎛. At this time, the temperature of the cooling roll was maintained at 30 ℃ and the sheet was preheated at 80 ℃ for 30 seconds and then simultaneously stretched biaxially to evaluate the elongation and transparency and the results are shown in <Table 1>.

(Comparative Example 1)

Into a 40L reactor, 1.0 kg of ε-caprolactam, 4.34 kg and 4.66 kg of m -xylenediamine and adipic acid were added, and 2.0 kg of water was added. The mixture was stirred without adding montmorillonite and the temperature was raised to 250 ° C. Maintained at 14kg / cm ² and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² to prepare a chip, which was washed with water at 95 ° C. for 12 hours to remove unreacted material, and then vacuum dried at 100 ° C.

The dried chip was prepared in the same manner as in Example 1, and then stretched to evaluate elongation and transparency, and the results are shown in Table 1.

(Example 2)

Into a 40L reactor, 1.0 kg of AH-salts (Hexamethylenediamine adipate), 4.34 kg and 4.66 kg of m -xylenediamine and adipic acid were added respectively, followed by 300 g of montmorillonite (Closis 15A, 125 meq / 100 g) from Southern Clay Products and 2.0 kg of water. The mixture was stirred to increase the temperature to 250 ° C., maintained at 14 kg / cm ² , and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² , and the polymer was manufactured into chips, which were vacuum dried at 100 ° C.

The dried chip was prepared in the same manner as in Example 1, and then stretched to evaluate elongation and transparency, and the results are shown in Table 1.

(Example 3)

300 g of montmorillonite (Geunminesa Gunipia-F, 119 meq / 100 g) and 1.0 kg of ε-caprolactam were added to the treatment tank, and 41.16 g of 85% phosphoric acid was added to 1.0 kg of water, and then the temperature was increased while stirring. It was allowed to reach ℃. The speed of the stirrer was stirred at 150 rpm for at least 3 hours so that montmorillonite was uniformly dispersed in the dispersion medium of water and ε-caprolactam. 4.34kg and 4.66kg of m -xylenediamine and adipic acid were added to the 40L reactor, 1kg of water was added, and the reactor was heated to 90 ° C. Transported by.

After the transfer was completed, the mixture of the reactor was stirred and the temperature was raised to 250 ° C. to maintain 14 kg / cm ² and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² to prepare a chip, which was washed with water at 95 ° C. for 12 hours to remove unreacted material, and then vacuum dried at 100 ° C.

The dried chip was prepared in the same manner as in Example 1, and then stretched to evaluate elongation and transparency, and the results are shown in Table 1.

(Comparative Example 2)

300 g of montmorillonite (Gumine M. Gunipia-F, 119 meq / 100 g) and 1,500 g of ε-caprolactam were added to a treatment tank, and 41.16 g of 85% phosphoric acid was added to 500 g of water, and then the temperature was raised while stirring to increase the temperature. To reach. The speed of the stirrer was stirred at 150 rpm for at least 3 hours so that montmorillonite was uniformly dispersed in the dispersion medium of water and ε-caprolactam. After adding 8.5 kg of ε-caprolactam and 2 kg of water to the 40L reactor, the reactor was heated to reach a temperature of 90 ° C., and the mixture of the previously prepared treatment tank was transferred by pressurization of nitrogen.

After the transfer was completed, the mixture of the reactor was stirred and the temperature was raised to 250 ° C. to maintain 14 kg / cm ² and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² to prepare a chip, which was washed with water at 95 ° C. for 12 hours to remove unreacted material, and then vacuum dried at 100 ° C.

The dried chip was prepared in the same manner as in Example 1, and then stretched to evaluate elongation and transparency, and the results are shown in Table 1.

(Comparative Example 3)

Into a 40L reactor, 4.0 kg of ε-caprolactam, 2.9 kg and 3.1 kg of m -xylenediamine and adipic acid were added, and 300 g of montmorillonite (Closis 15A, 125meq / 100g, Southern Clay Products) and 2.0 kg of water were added. The mixture was stirred and the temperature was raised to 250 ° C. to maintain 14 kg / cm ² and reacted for 1 hour. Subsequently, the pressure in the reactor was gradually removed for 1 hour to create an atmospheric pressure, and the polymerization was completed by reducing the pressure at -0.3 kg / cm ² for 30 minutes. After the polymerization was completed, the polymer was discharged by pressurization of 5 kg / cm ² to prepare a chip, which was washed with water at 95 ° C. for 12 hours to remove unreacted material, and then vacuum dried at 100 ° C.

The dried chip was prepared in the same manner as in Example 1, and then stretched to evaluate elongation and transparency, and the results are shown in Table 1.

Example 1 Comparative Example 1 Example 2 Example 3 Comparative Example 2 Comparative Example 3 Polyamide Resin (100 parts by weight) MXD-6 / nylon 6 (90/10) MXD-6 / nylon 6 (90/10) MXD-6 / nylon 66 (90/10) MXD-6 / nylon 6 (90/10) MXD-6 / Nylon 6 (0/100) MXD-6 / nylon 6 (60/40) Montmorillonite (parts by weight) Cloisite 15A (3.0) - Cloisite 15A (3.0) Guinea-F (3.0) Guinea-F (3.0) Cloisite 15A (3.0) Solidification speed X X Extensibility X transparency(%) 92 87 90 88 78 89 Oxygen permeability (cc / m ² 24hr) 5.6 8.1 6.1 4.0 19.2 15.7

By preparing nanocomposites of montmorillonite-containing copolymer polyamide resins from a mixture of monomers and montmorillonite, it is possible to obtain a resin composition of copolymer polyamide having excellent dispersibility and excellent gas barrier properties, transparency, and particularly excellent elongation at low temperatures. It became.

Claims (3)

100 wt% of the equivalent mixture of m -xylenediamine and adipic acid constituting the MXD-6 nylon, and 100 wt% of the polyamide polymer comprising 0.1-30 wt% of the monomer capable of forming polyamide in addition to the above monomers. The polyamide resin composition characterized by copolymerizing after adding 0.5-10 weight part of montmorillonite with respect to a part. The monomer of claim 1, wherein the monomer capable of forming a polyamide other than MXD-6 nylon is selected from the group consisting of ε-caprolactam, tetramethylenediamine, hexamethylenediamine, terephthalic acid, isophthalic acid, 12-aminododecanoic acid. And produced by melt polymerization of these raw materials. The montmorillonite according to claim 1, wherein the montmorillonite has a structure in which platelets are laminated with an interlaminar distance of 10 [mu] s, or the distance between the plates is expanded to [epsilon] -caprolactam, 12-aminododecanoic acid, octadecylamine, and tallow ammonium ions. Polyamide resin composition characterized in that the adjusted.