KR20020055985A - Polyamide resin composition including montmorillonite - Google Patents

Abstract

PURPOSE: Provided are a method for mixing montmorillonite with epsilon-caprolactam, which is a monomer of polyamide resin and water and easily dispersing the montmorillonite, and a complex having excellent dispersion in a polyamide resin. CONSTITUTION: The polyamide resin composition comprises 100 wt% of polyamide polymer consisting of 70-100 wt% of epsilon-caprolactam and 0-30 wt% of other monomer capable of forming a polyamide; and 0.5-10 wt% of montmorillonite. The other monomer capable of forming a polyamide is a mixture of at least one selected from the group consisting of tetramethylene diamine, hexamethylene diamine, and xylene diamine, and at least one selected from the group consisting of terephthalic acid, isophthalic acid and 12-aminododecanoic acid, or 12-aminododecanoic acid.

Description

Polyamide resin composition including montmorillonite

The present invention relates to a resin composition of polyamide including montmorillonite having a structure of laminated silicates, and more particularly, to preparing a polyamide from a mixture of monomers capable of forming polyamide and montmorillonite, thereby providing mechanical strength and heat resistance. The present invention relates to a resin composition of polyamide having excellent gas barrier properties and improved crystallization rate.

Due to the strong interaction and swellability of the laminated silicate structures, the montmorillonite has difficulty in achieving uniform dispersion with the monomers of the polyamide and water used in the production of the polyamide, resulting in uniform fine dispersion in the polyamide resin. There is a difficult problem.

The present invention relates to a method of easily dispersing montmorillonite having such properties by mixing with ε-caprolactam, which is a monomer of polyamide, and water, and to a polyamide resin composition through which montmorillonite can be uniformly dispersed in a resin. .

Polyamide resin is a resin that is widely used as a material for automotive and electronic parts and food packaging because of its excellent mechanical strength, chemical resistance and gas barrier property.

In order to further improve these properties and to impart properties such as hygroscopicity, dimensional stability, and flame retardancy to polyamides, many methods have been additionally processed by adding inorganic materials by extrusion kneading. Although it is advantageous to improve certain properties, it was difficult to maintain the advantages of the existing polyamide.

U.S. Patent No. 5,102,948 proposes a method of pretreating montmorillonite to increase the interlayer distance of silicates and then obtaining a composite by mixing with polyamide resin. After the step and pretreatment, there is a problem in that the manufacturing step is complicated by the process of mixing ε-caprolactam, mixing with water, and montmorillonite treated with an extruder with polyamide resin.

In US Pat. No. 5,248,720, a composite is prepared by mixing montmorillonite with a monomer of a polyamide to prepare a complex. I'm suggesting how.

However, the above method requires a separate step of pretreatment and recovery of montmorillonite, and since the swelling property of montmorillonite is large, it is necessary to use excess water in order to disperse it in water. The problem is that the efficiency of the reaction is reduced and the reaction time is long.

The present invention is to overcome the above problems, a method that can be easily dispersed by mixing montmorillonite with ε-caprolactam, a monomer of the polyamide resin, water, and finally a composite having excellent dispersibility in the polyamide resin It is about.

In other words, montmorillonite has a laminated structure due to the strong interaction between the plates, and this results in excessive swelling, and by using a treatment agent that can replace the interaction between the plates, the interaction between the plates and the treatment agent It is intended to provide a polyamide resin composition containing montmorillonite that solves the swelling property by interfering with the bond to obtain the admixture with water and ε-caprolactam.

The polyamide resin composition according to the present invention is nylon 6 or polyamide copolymerized from 70 wt% to 100 wt% of ε-caprolactam, which is a main component of nylon 6, and from 0 to 30 wt% of monomers capable of forming other polyamides. It consists of 100% by weight of water and 0.5-10% by weight of montmorillonite,

In addition, montmorillonite is mixed with a small amount of a dispersion medium and a pretreatment agent in a separate treatment tank, and then mixed with a monomer of polyamide to form a polyamide, thereby increasing the efficiency of the reactor and dispersing montmorillonite with a polyamide resin composition. It is about.

Hereinafter, the present invention will be described in detail.

Polyamide is composed of nylon 6 as a main component and 0.5 to 10% by weight based on 100% by weight of nylon 6 or polyamide copolymer, in which the component by the monomer capable of forming polyamide is 0 to 30% by weight in the polyamide resin. Consists of montmorillonite.

Monomers of the polyamide in the present invention are ε-caprolactam, tetramethylenediamine, hexamethylenediamine, m -xylenediamine, adipic acid, terephthalic acid, isophthalic acid, 12-amino dodecanoic acid and the like.

The montmorillonite used in the present invention has a very large aspect ratio of about 1000 times and has a strong binding force with the polyamide resin, which is advantageous for obtaining the desired effect of the present invention, and the montmorillonite is used with respect to 100% by weight of the polyamide polymer. It is used in an amount of 0.5 to 10% by weight.

At this time, when less than 0.5% by weight, it is difficult to obtain the desired effect of the present invention, and when it exceeds 10% by weight, since the melt viscosity of the polymer is increased by montmorillonite having a large value of appearance ratio, there is 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-amino dodecanoic acid, octadecylamine, ammonium ions of tallow and the like can be used.

In the present invention, the montmorillonite is reacted or mixed with ε-caprolactam, phosphoric acid, and water in the treatment tank to increase the distance between the plates, thereby reducing its swelling and performing uniform dispersion, followed by mixing with the monomers of polyamide for polymerization. Polyamide was prepared by the method.

According to this method, the recovery process of montmorillonite is not necessary, and there is an advantage of reducing the amount of water used about 30 to 50 times as a dispersion medium of montmorillonite.

That is, 300-1,000 weight% of epsilon caprolactam and 150-500 weight% of water are added with respect to 100 weight% of montmorillonite, and the combined amount is 450-1,500 weight%, and phosphoric acid is 1 with respect to the ion exchange capacity of montmorillonite. After adding the equivalents and stirring, it is easy to obtain uniform dispersion results.

At this time, when the amount of ε-caprolactam to be used is less than 300% by weight, the dispersion effect of montmorillonite is reduced, and when used in excess of 1000 parts by weight, the size of the preparation is increased, the amount of water and ε-capro as a dispersion medium The amount of lactam is 450 to 1500% by weight relative to 100% by weight of montmorillonite, wherein the preparation temperature is suitably 70 to 140 ° C.

In the present invention, a polymerization process for producing a resin composition of polyamide is as follows.

[One]. Montmorillonite, ε-caprolactam, phosphoric acid, and water are added to the treatment tank and heated with stirring to form a uniform dispersion.

[2]. Into the reactor, the monomers forming the epsilon caprolactam and other polyamides are introduced at a desired composition ratio and water is added to make it equal to the temperature of the treatment tank.

At this time, the amount of ε-caprolactam is calculated by summing up the amounts of the reactor and the preparation to make the polyamide polymer of the desired composition as a whole.

[3]. The mixture of the treatment tank is transferred to the reactor, and then heated to raise the temperature, to maintain a pressurized state for the reaction, to gradually remove the pressure of the reactor to make a normal pressure.

[4]. After depressurizing the desired molecular weight level, the reactor is pressurized to discharge the polymer.

[5]. The polymer is extracted in the maximum bath ratio and then dried to obtain the final polyamide composition.

At this time, the relative viscosity of the polyamide resin used in the present invention is preferably in the range of 1.8 to 4.0.

That is, when the relative viscosity is less than 1.8, the mechanical properties of the resin composition are lowered due to the influence of molecular weight, and when the relative viscosity is higher than 4.0, the workability of the resin composition is inferior.

Hereinafter, an embodiment of the present invention will be described in detail, but the present embodiment should not be regarded as limiting the present invention.

Example 1

300 g of montmorillonite (Kuneminesa 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

And the speed | rate of the stirrer was made to 150 rpm, and it stirred for 3 hours or more, and the montmorillonite was disperse | distributed uniformly to the dispersion medium of water and (epsilon) -caprolactam.

Thereafter, 8.5 kg of ε-caprolactam and 2 kg of water were added to the 40-L reactor, and the reactor was heated to reach a temperature of 90 ° C., and then the mixture of the previously prepared treatment tank was transferred by pressurization of nitrogen.

When the transfer is complete, the mixture of the reactor is stirred and the temperature is raised to 250 ° C. and maintained at 14 kg / cm ² and reacted for 1 hour.

Here, the pressure in the reactor was slowly removed for 1 hour to create an atmospheric pressure, and then the pressure was reduced to 30 minutes at a pressure of -0.3 kg / cm ² to complete the polymerization.

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 120μm.

At this time, the temperature of the cooling roll was maintained at 30 ℃ and preheated the prepared sheet at 80 ℃ for 30 seconds and stretched by 2.5 times at the same time biaxially to evaluate the oxygen permeability and the results are shown in Table 1.

Comparative Example 1

300 g of montmorillonite (Geunminesa Gunipia-F, 119 meq / 100 g) and 500 g of ε-caprolactam were added to a treatment tank, and 41.16 g of 85% phosphoric acid was diluted and added to 300 g of water, followed by dispersion as in Example 1.

In the 40L reactor, 9.5 kg of ε-caprolactam and 2 kg of water were added, and when the temperature of the reactor reached 90 ° C, a polyamide polymer was prepared in the same manner as in Example 1 to evaluate properties.

Comparative Example 2

300 g of montmorillonite (Geunminesa Gunipia-F, 119 meq / 100 g) and 1,500 g of ε-caprolactam were added to a treatment tank, and 13.72 g of 85% phosphoric acid was added to 500 g of water, followed by dispersion as in Example 1. . In the 40L reactor, 8.5 kg of ε-caprolactam and 2 kg of water were added, and when the temperature of the reactor reached 90 ° C., a polyamide polymer was prepared in the same manner as in Example 1 to evaluate properties.

Example 2

300 g of montmorillonite (Clonisite 15A, 125meq / 100g) of Southern Clay Products and 1,500 g of ε-caprolactam were added to a treatment tank, and 43.24 g of 85% phosphoric acid was added to 500 g of water, followed by dispersion as in Example 1.

In the 40L reactor, 8.5 kg of ε-caprolactam and 2 kg of water were added, and when the temperature of the reactor reached 90 ° C, a polyamide polymer was prepared in the same manner as in Example 1 to evaluate properties.

Example 3

600 g of montmorillonite (Geunminesa Gunipia-F, 119 meq / 100 g) and 2,000 g of ε-caprolactam were added to the preparation, and 82.32 g of 85% phosphoric acid was added to 1,000 g of water, followed by pretreatment as in Example 1. It was. After adding 8.0 kg of ε-caprolactam and 2 kg of water to the 40L reactor, a polyamide polymer was prepared in the same manner as in Example 1 to evaluate properties.

Example 4

600 g of montmorillonite (Croisite 15A, 125meq / 100g) and 2,000 g of ε-caprolactam were added to a treatment tank, and 86.48 g of 85% phosphoric acid was diluted and added to 1,000 g of water, followed by dispersion as in Example 1. .

In a 40L reactor, 6.0 kg of ε-caprolactam, 0.98 kg of m -xylenediamine, 1.04 kg of adipic acid and 2 kg of water were added, and when the temperature of the reactor reached 90 ° C., a polyamide polymer was prepared in the same manner as in Example 1. The properties were evaluated.

Example 1 Comparative Example 1 Comparative Example 2 Example 2 Example 3 Example 4 Polyamide Resin (part by weight) Nylon 6 (100) Nylon 6 (100) Nylon 6 (100) Nylon 6 (100) Nylon 6 (100) Nylon 6 / MXD6 (80/20) Montmorillonite (parts by weight) 3.0 3.0 3.0 3.0 6.0 6.0 Tensile Strength (kg / cm ² ) 1,040 820 780 940 1,150 1,120 % Elongation 65 75 56 30 3 63 Flexural Strength (kg / cm ² ) 1,540 1,150 1,080 1,400 1,820 1,670 Flexural modulus (kg / cm ² ) 36,200 28,200 25,300 37,800 51,800 46,400 Heat deflection temperature (℃) 132 98 82 129 165 119 Impact strength (kgcm / cm) 3.9 3.7 3.5 4.8 3.6 5.3 Oxygen permeability (cc / m ² 24hr) 19.2 26.1 33.6 20.7 12.5 6.6

According to the present invention, a polyamide may be prepared from a mixture of monomers capable of forming polyamide and montmorillonite to prepare a resin composition of polyamide having excellent mechanical strength, heat resistance, gas barrier properties, and improved crystallization rate. there was

In addition, by using a treatment agent that can replace the interaction between the plates, the swelling was solved by preventing the binding between the plates by the interaction of the plate and the treatment agent, thereby improving the mixing of water and ε-caprolactam.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (4)

Montmorillonite, characterized in that it comprises 0.5 to 10% by weight of montmorillonite based on 100% by weight of the polyamide polymer consisting of 70 to 100% by weight of ε-caprolactam and 0 to 30% by weight of other monomers capable of forming polyamide. Polyamide resin composition. The method of claim 1, wherein the other monomer capable of forming a polyamide, Mixtures or alone consisting of one selected from the group consisting of tetramethylenediami, hexamethylenediamine and m -xylenediamine and one selected from the group consisting of adipic acid, terephthalic acid, isophthalic acid and 12-aminododecanoic acid The polyamide resin composition comprising montmorillonite, characterized in that 12-aminododecanoic acid. According to claim 1, wherein the montmorillonite is added to 300 to 1,000% by weight of ε-caprolactam, 150 to 500% by weight of water with respect to 100% by weight of montmorillonite, and dispersed in 1 equivalent of a phosphoric acid mixture with respect to the ion exchange capacity of montmorillonite Polyamide resin composition comprising montmorillonite, characterized in that the polymerization and use. The method according to any one of claims 1 to 3, wherein montmorillonite, The interlaminar distance is 10Å, and the plate-laminated structure or the distance between the plates is expanded to ε-caprolactam, 12-amino dodecanoic acid, octadecylamine, and ammonium ions of tallow to adjust their swelling properties and then polymerize them. A polyamide resin composition comprising montmorillonite characterized by the above.