KR20130078775A - Polyamide resin composition - Google Patents

Abstract

PURPOSE: A polyamide resin composition is provided to have extremely a low ion elution degree when exposed to a high temperature and high humidity environment and to have excellent mechanical performance, heat resistance, cold resistance, and high productivity. CONSTITUTION: A polyamide resin composition comprises 100.0 parts by weight of a polyamide resin, 10-40 part by weight of a polypropylene resin; 0.01-2 parts by weight of tetrakis[methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane; 0.01-2 parts by weight of N-[2- (octadecanoylamino) ethyl]octadecanamide; and 20-50 parts by weight of a glass fiber. The polyamide resin has a relative viscosity of 2.5-3.5 (20 °C, 1g of a resin component in 100 ml of 96% sulfuric acid) and includes at least one of nylon 6 and nylon 66.

Description

Polyamide resin composition {POLYAMIDE RESIN COMPOSITION}

The present invention relates to a polyamide resin composition that can be used as a humidifier material for fuel cells.

A fuel cell is a high-efficiency, pollution-free power generation device that directly converts chemical energy of hydrogen and oxygen into electrical energy by electrochemical reactions. The cathode is supplied to the cathode, and the anode is supplied with hydrogen to reverse the electrolysis of water. It proceeds and has the principle of generating electricity together with water and heat. Unlike conventional chemical batteries, such as batteries and accumulators, fuel cells can produce electricity continuously as long as hydrogen and oxygen are supplied, and they are twice as efficient as internal combustion engines because they have no heat loss. Therefore, the fuel cell is advantageous not only to be environmentally friendly, but also to reduce the fear of depletion of fossil fuel.

Such a fuel cell can be largely divided into a polymer electrolyte fuel cell, a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid oxide fuel cell, and an alkaline fuel cell depending on the type of electrolyte used.

One of the most important factors in improving the performance of a polymer electrolyte fuel cell is to maintain a water content by supplying an appropriate temperature and predetermined moisture to a polymer electrolyte membrane of a membrane-electrode assembly. This is because, when the polymer electrolyte membrane is dried, the power generation efficiency sharply drops.

In order to maintain an appropriate temperature and humidity environment in the polymer electrolyte membrane of the membrane-electrode assembly, a humidifier is essential.

The humidifier has a merit that the water vapor in the unreacted gas is supplied to the polymer electrolyte membrane using a membrane that selectively permeates only the water vapor contained in the unreacted gas in the polymer electrolyte membrane, and the humidifier can be made lighter and smaller. A hollow fiber membrane having a large permeation area per unit volume is preferable for such a selective permeable membrane.

The material used in the humidifying membrane method should not adversely affect the performance of the hollow fiber membrane. Ions degrade the performance of the membrane over time. Therefore, the ion should not be eluted from the humidifier material, and should be low even if it is eluted. Also, when applied to automobiles, the characteristics of automobile vibration, heat resistance, cold resistance, etc. should be good.

Various polymer materials have been proposed to satisfy these properties. In particular, since the high heat-resistant polyamide resin is excellent not only in mechanical properties but also in heat resistance or cold resistance properties, its use as a humidifier material has been recently proposed.

However, the high heat-resistant polyamide resin is not good in productivity because the cycle time is considerably long due to the high melting temperature during product molding.

Therefore, in recent years, development of a material for a humidifier which is capable of shortening a molding cycle time which satisfies both low ion elution degree, mechanical property, heat resistance and cold resistance characteristic, which is an advantage of a high heat resistant polyamide resin, is required.

The present invention is to provide a polyamide resin composition that can be applied as a fuel cell humidifier for automobiles having not only a very small ion dissolution but also excellent mechanical properties, heat resistance, cold resistance, and high productivity even when exposed to a high temperature and high humidity environment for a long time. do.

Accordingly, the present invention provides, as a first preferred embodiment, a polyamide resin; 10 to 40 parts by weight of polypropylene resin, based on 100 parts by weight of the polyamide resin; 0.01 to 2 parts by weight of Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane; It provides a polyamide resin composition comprising 0.01 to 2 parts by weight of N- [2- (octadecanoylamino) ethyl] octadecanamide and 20 to 50 parts by weight of glass fiber (GLASS FIBER).

The polyamide resin according to the above embodiment may have a relative viscosity (20 ° C., 1 g of a resin component in 100 ml of 96% sulfuric acid) of 2.5 to 3.5, and may include at least one of nylon 6 and nylon 66.

The polyamide resin composition according to the embodiment may further include one or more additives selected from the group consisting of nucleating agents, compatibilizers and pigments.

The polyamide resin composition according to the above embodiment has a tensile strength of 1,000 kg / cm 2 or more based on ASTM D638, a bending strength of 1,500 kg / cm 2 or more based on ASTM D790, and a heat deformation temperature of 4.6 kg / according to ASTM D648. after the surface area in cm ² load at more than 150 ℃, DIELECTRIC WATER 200ML, 80 o C to produce a deposition environment 80cm ³ of the specimen after 1500 hours have ionic conductivity may be not more than 65 micro-Siemens.

The polyamide resin composition according to the present invention does not significantly change the mechanical properties even after being left in a long time vibration environment, high temperature, low temperature environment, and has excellent physical and heat resistance properties, thereby maintaining and improving the performance of the fuel cell device. It can be easily applied to a humidifier.

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

The present invention relates to a polyamide resin composition, 10 to 40 parts by weight of polypropylene resin, based on 100 parts by weight of the polyamide resin; 0.01 to 2 parts by weight of Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane; It relates to a polyamide resin composition comprising 0.01 to 2 parts by weight of N- [2- (octadecanoylamino) ethyl] octadecanamide and 20 to 50 parts by weight of glass fiber (GLASS FIBER).

The polyamide resin refers to a thermoplastic resin containing an amide group (-CONH-). In one embodiment of the invention, the polyamide resin has nylon 6, nylon 66 and mixtures thereof having a relative viscosity of 2.5 to 3.5. It provides a polyamide resin composition comprising a.

Such a polyamide resin may have a relative viscosity of 2.5 to 3.5 (1 g of a resin component in 100 ml of sulfuric acid at 96 ° C. at 20 ° C.), and when the relative viscosity is less than 2.5, stiffness and heat resistance may be lowered. In high-speed production, excessive frictional heat between the screw and the resin is generated, and the resin is decomposed or high pressure is required for molding, which may cause excessive molding to the molding machine and the mold, which may make injection molding difficult.

In addition, in one embodiment of the invention, to reduce the ion dissolution of the polyamide resin composition may comprise a polypropylene resin. The polypropylene resin may include 10 to 40 parts by weight, preferably 10 to 30 parts by weight based on 100 parts by weight of the polyamide resin. When the raw material is included in less than 10 parts by weight based on 100 parts by weight of the polyamide resin, the effect of lowering the ion conductivity is not obtained, and when included in excess of 40 parts by weight, the rigidity of the product may be greatly reduced.

In one embodiment of the present invention, Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane may be included to improve the heat resistance of the polyamide resin composition. The mixture may be applied together with GLASS FIBER which will be described later to improve heat resistance and mechanical properties at the same time.

Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane may be represented by the following Chemical Formula 1.

[Formula 1]

The Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane is contained in an amount of 0.01 to 2 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the polyamide resin. can do. When included in less than 0.01 part by weight based on 100 parts by weight of the polyamide resin, the effect of improving heat resistance cannot be obtained, and even when contained in excess of 2 parts by weight, the effect of improving heat resistance may be insignificant.

In addition, in one embodiment of the invention, to improve the releasability of the polyamide resin composition may include N- [2- (octadecanoylamino) ethyl] octadecanamide.

The N- [2- (octadecanoylamino) ethyl] octadecanamide may be represented by the following Chemical Formula 2.

(2)

The N- [2- (octadecanoylamino) ethyl] octadecanamide may be included in an amount of 0.01 to 2 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the polyamide resin. If the secondary raw material is included in less than 0.01 parts by weight with respect to 100 parts by weight of the polyamide resin, the effect of improving releasability cannot be obtained. If the secondary raw material is included in excess of 2 parts by weight, surface defects such as GAS marks appear on the surface of the product.

Glass fiber used in the present invention is a glass fiber that is commonly used, in the Chop-type glass fiber is only 3 to 6mm in length, the main component is CaOSiO2Al2O3, CaO is 10 to 20 parts by weight, SiO ₂ is 50 to 70 By weight, Al ₂ O _{3 It} is composed of 2 to 15 parts by weight. Preferably, the surface of the glass fiber is subjected to coupling treatment with silane for the purpose of interfacial adhesion with the final composition, and the glass fiber having a diameter of 10 to 13 mu m can be used. Glass fiber used in the composition of the present invention was used by KCC brand name "CS-311", the addition amount is 20 to 50 parts by weight of the total resin composition. If the amount is less than 20 parts by weight, the tensile strength and the flexural strength are inferior. If the content is more than 50 parts by weight, the surface defect or the ionic conductivity of the molding may be increased.

As shown in the experimental examples described below, the tensile strength was 1,000 kg / cm 2 or more based on ASTM D638, the flexural strength was 1,500 kg / cm 2 or more based on ASTM D790, and the heat deformation temperature was 4.6 kg / cm based on ASTM D648. Polyamide resin composition having a polyamide resin composition of 150 ° C. or higher at a load of ² ° C. and having a surface area of 80 cm ³ in a DIELECTRIC WATER 200ML, 80 ^° C. environment, having a surface area of 80 cm ³ and depositing a polyamide resin having an ion conductivity of 65 micro Siemens or less after 1500 hours. To provide a composition.

The polyamide resin composition described above can be easily applied to a humidifier because it does not significantly change the mechanical properties even after being left in a long time vibration environment, high temperature, low temperature environment and has excellent physical and heat resistance properties.

Polyamide resin, polypropylene resin, Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, N- [2- (octadecanoylamino) ethyl] octadecanamide and GLASS FIBER It may be prepared by melt kneading at to 270 ℃.

If the temperature of the melt-kneading is less than 240 ° C., the melting point of the polyamide resin becomes substantially similar to the melting point of the polyamide resin. As a result, the additive or the polyamide resin may be thermally decomposed or volatilized. You can.

For the production of the polyamide resin composition, a commonly used melt-kneading method and equipment can be used. Specific examples of the equipment used for such melt-kneading include a uniaxial or biaxial screw extruder, Two or more injection ports may be provided for one kneading. In the case of using a single screw or twin screw extruder having such first and second inlets, the first inlet is a polyamide resin and a heat-resistant agent, and the second inlet is GLASS FIBER. It is preferable because the effect of uniform kneading by the shear of the screw can be brought.

In order to reduce the volatilization of the additive during melt kneading and to maximize the physical properties of the composition, it is desirable to minimize the residence time in an apparatus such as an extruder. In addition, a nucleating agent, a pigment, or a mixture thereof may be added through the primary inlet in a range that does not violate the object of the present invention.

The polyamide resin composition as described above can be easily applied to a humidifier because it has excellent physical properties and thermal resistance characteristics without significantly changing its mechanical properties even when it is left in a vibration environment for a long time, a high temperature and a low temperature environment.

Hereinafter, the present invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

Examples 1-7

In the primary raw material inlet of the twin screw extruder heated to 240 ~ 270 ° C, nylon 6 resin (relative viscosity 2.75), polypropylene resin, Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, N- [2- (octadecanoylamino) ethyl] octadecanamide was added to the composition of Table 1 below, and a polyamide resin composition was prepared through a hot melt kneading process.

After melt kneading, the polyamide resin composition was made into chips and dried at 80 ° C. for 4 hours using a dehumidifying dryer.

Comparative Examples 1 to 4

Except for adjusting the content of each component in the following Table 1, a polyamide resin composition was prepared in the same manner as in the above embodiment, made into a chip state and dried.

 Composition of Polyamide Resin Compositions of Examples and Comparative Examples division Content by weight (% by weight) Nylon 6 PP GLASS FIBER Heat-resistant Release agent Example 1 100 10 30 0.1 0.1 Example 2 100 30 30 0.1 0.1 Example 3 100 40 30 0.1 0.1 Example 4 100 30 20 0.1 0.1 Example 5 100 30 50 0.1 0.1 Example 6 100 30 40 One 0.1 Example 7 100 30 40 One One Comparative Example 1 100 3 30 0.1 0.005 Comparative Example 2 100 30 10 0.1 0.1 Comparative Example 3 100 45 30 0.005 0.1 Comparative Example 4 100 45 55 2.5 2.5

After evaluating the physical properties and the ionic conductivity of the polyamide resin composition obtained in the above Examples and Comparative Examples based on the following evaluation criteria, the results are shown in Table 2.

(1) Tensile strength: Measured after fabricating 1/8 inch specimen in accordance with ASTM D638, the value less than 1,000 kg / cm ² was determined to be defective.

(2) Flexural strength: measured after fabricating 1/8 inch specimens in accordance with ASTM D790, the value less than 1,500 kg / cm ² was determined to be defective.

(3) Heat deformation temperature: A 1/4 inch specimen was prepared according to ASTM D648, and a value less than 150 ° C at a load of 4.6 kg / cm ² was judged to be defective.

The physical properties of the polyamide resin composition obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were measured based on the above-described property evaluation criteria.

(4) Ion Conductivity: Using the polyamide resin compositions of the above Examples and Comparative Examples, a specimen having a surface area of 80 cm ³ was completely deposited on DIELECTRIC WATER 200ML, and then ion conductivity was obtained after 1500 hours in an 80 ^° C. environment. Measured.

Physical and ion conductivity test results The tensile strength
(Kg / cm2) Flexural strength
(Kg / cm2) Heat distortion temperature
(℃) Ion conductivity
(μS) Remarks Example 1 1520 2314 203 60 - Example 2 1321 2007 159 58 - Example 3 1189 1867 152 45 - Example 4 1050 1712 160 53 - Example 5 1560 2290 179 63 - Example 6 1385 2062 161 55 - Example 7 1356 2039 163 56 - Comparative Example 1 1652 2567 215 110 Mold release defect Comparative Example 2 920 1560 145 45 - Comparative Example 3 1110 1721 142 42 - Comparative Example 4 1325 2110 165 55 Molding impossible

As shown in Table 2, in Examples 1 to 7, including a polyamide resin and a polypropylene resin and a glass fiber, a heat-resistant supplement, a release agent according to the present invention in a specific composition ratio, the content ratio of each component is Compared with Comparative Examples 1 to 4 out of the range, it can be seen that they have excellent properties at the same time in terms of physical properties such as tensile strength, flexural strength, heat deformation temperature, and ionic conductivity.

Claims (4)

Polyamide resins;
Per 100 parts by weight of the polyamide resin,
10 to 40 parts by weight of polypropylene resin;
0.01 to 2 parts by weight of Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane;
0.01 to 2 parts by weight of N- [2- (octadecanoylamino) ethyl] octadecanamide and
Polyamide resin composition comprising 20 to 50 parts by weight of glass fiber (GLASS FIBER). The method of claim 1,
The polyamide resin is a polyamide resin composition, characterized in that the relative viscosity (20 g, 1 g of the resin component in 100 ml of 96% sulfuric acid) 2.5 to 3.5, and at least one of nylon 6 and nylon 66. The method of claim 1,
A polyamide resin composition further comprising at least one additive selected from the group consisting of nucleating agents, compatibilizers and pigments. The method of claim 1,
Tensile strength of 1,000㎏ / ㎠ or more according to ASTM D638,
Flexural strength according to ASTM D790 is not less than 1,500 kg / ㎠,
Heat deflection temperature in accordance with ASTM D648 is 150 ℃ or more at 4.6kg / cm ² load,
DIELECTRIC WATER 200ML, Polyamide resin composition having an ion conductivity of 65 micro Siemens or less after 1500 hours after fabricating and depositing a specimen having a surface area of 80 cm ³ in an environment of 80 ^o C.