KR970010474B1 - Polyamide resin composition - Google Patents

Abstract

The invention provides a polyamide resin composition which have a high tenacity, high heat resistance, high impact resistance and high bending strength. The resin is obtained by: mixing 40-90% by weight of a crystalline polyamide having a melting temperature of 200-270 C and 10-60% by weight having a glass transition temperature of 190 C or more; melting and mixing the mixture and 0.3-7 parts of polyolefine group synthetic rubber based on the weight of the mixture of which the main component is ethylene-prophylene; following by conventional way.

Description

Polyamide resin composition excellent in toughness and heat resistance

The present invention relates to a polyamide resin composition having excellent toughness and heat resistance as a main component of polyamide, polyetherimide, and olefin synthetic rubber.

More specifically, in the present invention, by adding a small amount of polyolefin-based synthetic rubber as a compatibilizer to a mixture of polyamide and polyetherimide, the thermal deformation, impact resistance, tensile strength, flexural strength, dimensional stability and hygroscopicity of polyamide resin are greatly increased. An improved thermoplastic resin composition is disclosed.

Polyamide resin is an engineering plastic with excellent wear resistance, chemical resistance, electrical properties, and mechanical properties, and is widely used as a component material for the electrical, electronic, mechanical, and automotive industries.

However, when a polyamide resin is used for a long time at a high temperature, various problems such as rapid deterioration of mechanical properties, deformation of the molded article, or carbonization of the surface are caused by heat and oxidation, as well as crack propagation due to impact. It has several disadvantages such as low resistance against notch and notch, low impact resistance and dimensional stability in dry condition, and high hygroscopicity.

In addition, polyetherimide resin is one of high performance special engineering plastics with excellent dimensional stability, mechanical properties, electrical properties, heat deformation resistance, heat resistance and water resistance, but has disadvantages such as poor chemical resistance, processability, impact resistance, and economic efficiency. .

In the past, these resins were mixed to improve the disadvantages while using the advantages of these resins. As an example, a method for producing a resin mixture by simple melt mixing is described in WO 84/03894. However, polyamide and polyetherimide resins have poor compatibility in terms of properties, and thus, by simply mixing them, molded articles having excellent mechanical strength and heat resistance could not be obtained. Therefore, in order to improve compatibility, the composition polymer may be modified or a small amount of other materials may be used. Some examples are as follows.

International Patent Publication No. 88/06170 discloses a material obtained by mixing polyetherimide and polyamide by adding a small amount of a phenol compound as a compatibility improving agent. Although these materials may have improved dimensional stability or hygroscopicity due to improved compatibility, molding processability is extremely poor and heat deformation under large loads is not sufficiently improved. In addition, a method of preparing a polyamide resin composition composed of polyphenylene ether and a rubbery block copolymer has been proposed to improve the disadvantages of polyamide (Korean Patent Publication No. 90-1382).

However, the impact resistance is greatly improved by this method, but since a large amount of copolymers prepared from polyphenylene ether and vinyl aromatics and conjugated diene monomers must be used, there is a disadvantage that the thermal deformation resistance is not sufficiently improved due to thermal stability.

In addition, the polyamide resin is alloyed with nylon 4 and 6 to improve rigidity and moldability (Korean Patent Publication No. 91-3772), or the ethylene-methacrylic acid copolymer (polypropylene 79-31497), Various modification methods have been proposed, including polypropylene resins (JP-A-79-103496), modified olefin resins modified with carboxylic acids, silicone-based polymers (Korean Patent Publication No. 92-2638), and the like. By the way, the impact resistance is improved, while the mechanical properties are degraded or the high viscosity of the synthetic rubber itself, especially when the content of the synthetic rubber is high, the workability is very bad and the heat resistance does not improve at all. A balanced polyamide resin composition having impact resistance, dimensional stability, hygroscopicity and workability at the same time cannot be obtained.

Accordingly, an object of the present invention is a high-performance polyamide resin composition in which the polyamide, polyether imide, and olefin-based synthetic rubber are melt-mixed to significantly improve heat deformation, impact resistance, flexural rigidity, dimensional stability, and hygroscopicity of polyamide. To provide.

The present inventors have conducted extensive research and found that the use of a small amount of polyolefin-based synthetic rubbers composed of olefin-based compounds of ethylene and propylene in the polyamide and polyetherimide compositions can alleviate the above disadvantages. Reached.

Polyolefin system having (C) ethylene-propylene as a main component to 100 parts of a mixed resin composition of (A) 20-95% by weight polyamide resin and (B) 5-80% by weight polyetherimide resin The polyamide resin composition which consists of 0.1-10 weight part of synthetic rubbers is provided.

The polyamide used in the composition of the present invention may be used as long as it has an amide group [-CO-HN-] in the main chain of the polymer and can be melted, but the crystalline polyamide having a melting temperature of 200 ° C to 270 ° C may be used. desirable. Representative examples thereof include nylon 4, nylon 5, nylon 6, 6, nylon 12, nylon, 6, 10, polyamide of terephthalic acid and trimethylhexane methylenediamine, polyamide obtained by the reaction of adipic acid and methaxylenediamine, Polyamides formed by the reaction of terephthalic acid with 4,4'-diaminocyclohexylmethane.

Among them, polyamide is particularly preferable for nylon 6, nylon 6, 6, nylon 6, 10 and the like.

Polyetherimide is a polymer composed of two kinds of ether bonds and imide bonds as essential binding units, and consists of repeating units represented by the following general formula.

In formula (1), n is the number of repeating units, indicating the size of the molecule, Z is a trivalent aromatic group, which is bonded to two adjacent carbons, and Ar and Y are each linked by a bivalent monocyclic aromatic or crosslinking member. The group of a false non-condensed bridging aromatic group is represented.

The aromatic polyetherimide used in the present invention contains bisphenol A, menaphenylenediamine, phthalic anhydride as a main component, and the production method thereof is described in "Polymer Preprint 24 (2), 312-313 (1983)". .

Representative examples of the aromatic polyetherimide include compounds represented by the following formulas:

In particular, the aromatic polyetherimide represented by the above formula (2) is commercially available from U.S. General Electric under the trade name Ultem.

On the other hand, polyolefin-based synthetic rubber used as a compatibilizer of the composition of the present invention must be finely dispersed at the interface of the separated phases to express excellent performance.

In the present invention, if the average particle diameter of the dispersed polyamide or polyetherimide is about 0.05 to 10 µm, compatibility is excellent. Such synthetic rubber reduces the interfacial energy at the separated phase interface and improves interfacial adhesion due to interaction with polyamide and hydrogen bonding with polyetherimide. Thus, the resin composition prepared according to the present invention is characterized by toughness, heat resistance, Excellent impact resistance and flexural strength.

Accordingly, as the polyolefin synthetic rubber that can be used in the composition of the present invention, a random copolymer in which two or more monoolefins are copolymerized as an amorphous or low crystalline rubber may be used. Ethylene prepared from ethylene and propylene as a main component -Propylene rubber (EPR) or dicyclopentadiene, 1,4-hexadiene, ethylidene norbornene, propenylnorbornene, cyclohexadiene or derivatives thereof in order to impart an unsaturated function as a third component thereto. Ethylene-propylene-diene monomer (EPDM) rubber is used. As the diene monomer, 5-ethylidene-2-norbornene, dicyclopentadiene and the like are mainly used.

The diene content of the EDPM rubber containing diene is 3% to 30% by weight, preferably 5% to 20% by weight.

The composition mixing ratio of the present invention is 20 to 95% by weight, preferably 40 to 90% by weight of polyamide and 5 to 80% by weight, preferably 10 to 60% by weight of polyetherimide and 100 parts of these resin mixtures. It is preferably made of 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight of polyolefin-based synthetic rubber.

When the content of the polyamide resin in the mixture is 20% by weight or less, the heat resistance deformation of the composition is improved, but the efficacy of the compatibilizer is decreased and the processing, forming and mechanical strength are greatly reduced due to the phase inversion. On the other hand, if the polyamide resin content is more than 95% by weight, not only the heat resistance deformation of the composition is poor under high loads, but also the polyetherimide resin is not completely melted during processing due to the large difference in melt viscosity between the two compositions. This is caused. In addition, the content of the polyolefin-based synthetic rubber which is a compatibilizer is 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, based on the total weight of the two components. If it is 0.1 part by weight or less of the copolymer, the effect is very low as a compatibilizer, and if it is 10 parts by weight or more, it acts as a component rather than a role as a compatibilizer, thereby greatly reducing the mechanical properties of the mixture.

As a mixer used to prepare the polyamide mixture of the present invention, an internal mixer, a single screw or twin screw extruder, or the like may be used, but most preferably a twin screw extruder. The temperature at the time of melt mixing may vary somewhat depending on the type of polyamide used and the composition ratio between polyamide and polyetherimide, but usually 265 ° C to 370 ° C, preferably 280 ° C to 350 ° C. Resin composition with improved mechanical properties such as toughness, heat resistance, etc., without significantly reducing the compatibilizer effect used in the present invention by using 10-50% of inorganic materials such as kaolin, talc, mica, carbon fibers, and glass fibers as fillers of the present composition. Can be obtained. In addition, the mixture of the present invention may include various additives used as pigments, stabilizers, antioxidants, lubricants, antistatic agents and other resin property improving agents.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The following example illustrates the synergistic effect of the product of the present invention by comparing the various property values according to the preparation method of the polyamide composition according to the present invention and the preparation method of the various controls. Accordingly, the embodiments described herein are intended to illustrate the method of the present invention and should not be construed to suggest the scope of use of the present invention.

For testing the polyamide / polyetherimide resin composition pellets prepared in Examples and Comparative Examples using a screw injection molding machine controlled at 270 ° C. to 370 ° C. to prepare samples for measuring various characteristic values by ASTM test method. Specimen was produced. Each specimen was tested according to the ASTM regulations of Table 1 and their results are shown in Table 2.

Example 1

50% by weight of nylon 6 pellets (Tongyang Nylon Co., Ltd., product name: TOPLAMID 1021 BRT) with a melting point of 219 ° C, glass transition temperature of 215 ° C, and polyetherimide pellets of standard grade (US General Electric Co., Product Name: ULTEM 1000) Ethylene-propylene-diene rubber (Compound Kumho Rubber Co., Ltd., product name: KEP570P, 15 weight% of 5-ethylidene-2-norbornene) as a compatibilizer to 50% by weight and 100 parts of these resins 1 The pellets were prepared by dry mixing the parts by weight and mixing and extruding with a biaxial extruder for melt mixing controlled at 290 ° C to 330 ° C. The pellets were dried in a vacuum hot air dryer at a temperature of 85 ° C. for 12 hours to prepare a test specimen for characteristics according to the above-described method, and various characteristic values were measured according to the conditions of Table 1, and the results are shown in Table 2.

Example 2

As a compatibilizer of Example 1, experiments were carried out in the same manner as in Example 1 except for the experiment using ethylene-propylene-diene rubber (manufactured by Kumho Tire Rubber Co., Ltd., KEP 860, containing 12 wt% of dicyclopentadiene). Each characteristic value was measured according to the conditions, and the results are shown in Table 2.

Example 3

Melting temperature 261 ° C, 50% by weight of nylon 6,6 (manufactured by Dongyang Nylon Co., Ltd., product name: TOPLAMID 2021 BRT), 50% by weight of polyetherimide (General Electric Co., trade name: ULTEM 1000) 1 part by weight of ethylene-propylene-diene rubber (trade name KEP 570P, manufactured by Kumhopi Rubber Co., Ltd.) containing 15% by weight of 5-ethylidene-2-norbornene with respect to 100 parts by weight of the resin was dried and mixed at 290 ° C to 340 ° C. The pellets were prepared by mixing and extruding the melt mixture controlled by a twin screw extruder. This was dried for about 12 hours at 95 ℃ using a vacuum hot air dryer to make a test specimen for characteristics according to the above-described method, and measured various characteristic values under the conditions of Table 1 and the results are shown in Table 2.

Example 4

Except for using KEP 570P used as a compatibilizer of Example 3, an ethylene-propylene-diene elastomer containing 6% by weight of 5-ethylidene-2-norbornene (Kumhopi Rubber Co., KEP 430) was used. Mixing was carried out according to the same method as in Example 3, and test specimens for characteristic tests were prepared. Each characteristic value was measured according to the provisions of Table 1, and the results are shown in Table 2.

Example 5

The composition and method of Example 3 were the same as those of Example 3, except that KEP-210 (manufactured by Kumhopi Rubber Co., Ltd.) containing 19% by weight of 5-ethylidene-2-norbornene was used instead of the compatibilizer KEP 570P. After mixing and fabricating the test specimen for properties, the characteristic values for this specimen were measured according to the provisions of Table 1, and the results are shown in Table 2.

Example 6

It was mixed in the same composition and method as in Example 3 except that KEP 370C (manufactured by Kumhopi Rubber Co., Ltd.) containing 26% by weight of 5-ethylidene-2-norbornene was used instead of the compatibilizer KEP 570P of Example 3. The test specimens were fabricated and the characteristic values for the specimens were measured in accordance with the provisions of Table 1 and the results are shown in Table 2.

Example 7

Except for using the KEP 860 used in Example 2 in place of the compatibilizer KEP 570P of Example 3 was tested in the same composition and method as in Example 3 and measured the various characteristics according to the provisions of Table 1 and the results are shown in Table 2 Indicated.

Example 8

Except having adjusted the weight ratio 50/50 of nylon 6,6 and polyetherimide of Example 3 to 70/30, it tested by the same composition and method as Example 3, and measured various specific value according to the provision of Table 1. The results are shown in Table 2.

Example 9

Except having adjusted the weight ratio 50/50 of nylon 6,6 and polyetherimide of Example 3 to 30/70, it was tested in the same composition and method as in Example 3 and measured various characteristic values according to the provisions of Table 1 The results are shown in Table 2.

Example 10-11

Except that the content of the compatibilizer KEP 570P of Example 3 was adjusted to 0.5 parts by weight (Example 10) and 5 parts by weight (Example 11), the experiment was carried out in the same manner as in Example 3, and various characteristics were determined according to the provisions of Table 1. It was measured and the results are shown in Table 2.

Example 12

Instead of KEP 570P, a compatibilizer of Example 3, the same composition as in Example 3 except for using an ethylene-propylene elastomer (trade name KEP 070P, manufactured by Kumhopi Rubber Co., Ltd.), containing no diene component and containing 27% by weight of propylene. Experimental methods were used to analyze and test each characteristic value according to the provisions of Table 1.

Comparative Example 1

Melting temperature 219 ℃, using a nylon 6 (TOPLAMID 1021 BRT) of medium viscosity grade only in the same manner as in Example 1 to measure each characteristic value in accordance with the conditions of Table 1 and the results are shown in Table 2 .

Comparative Example 2

Polyetherimide (Ultem-1000) pellets with a glass transition temperature of 215 ° C and a standard grade were dried at 150 ° C for 12 hours using a hot air dryer to prepare test specimens for characteristics according to the method described above. Various characteristic values were analyzed and tested, and the results are shown in Table 2.

Comparative Example 3

The experiment was performed in the same manner as in Example 1, but no polyethylene-propylene-diene rubber used as a compatibilizer was used. The experiment was performed in the same manner as in Example 1, and the characteristic values were measured according to the conditions of Table 1, and the results are shown in Table 2. It was.

[Comparative Example 4]

Melt temperature 216 ℃, medium grade nylon 6,6 (TOPLAMID 2021 BRT) pellets were dried for 24 hours at 85 ℃ using a vacuum hot air dryer to prepare a test specimen for characteristics according to the method described above Table 1 Various characteristic values were measured according to the regulations and are shown in Table 2.

[Comparative Example 5]

The same grade nylon 6,6 and polyetherimide used in Example 3 were tested in the same manner as in Example 3 except that the weight ratio was 50/50 and no compatibilizer was included. The analytical test was carried out according to the results shown in Table 2.

Comparative Example 6

Except that the weight ratio 50/50 of nylon 6,6 and polyetherimide of Example 3 was adjusted to 95/5, experiments were carried out by the same composition and method as in Example 3, and each characteristic value was tested according to the provisions of Table 1. The results are shown in Table 2.

Comparative Example 7

Except for adjusting the content of KEP 570P, a compatibilizer of Example 3 to 0.1 parts by weight, the experiments were conducted in the same manner as in Example 3, and each characteristic value was tested according to the provisions of Table 1, and the results are shown in Table 2.

Comparative Example 8

Except for adjusting the content of KEP 570P, a compatibilizer of Example 3 to 10 parts by weight, the experiment was carried out in the same manner as in Example 3, and each characteristic value was analyzed and tested according to ASTM. The results are shown in Table 2.

As shown in Table 2, when the resin of nylon 6 or nylon 660,000 contains 5% of polyetherimide, the heat deformation temperature is very low around 80 ° C., but when the polyetherimide contains 30%, the heat deformation temperature is 100 ° C. or more. It is greatly increased. In addition, when a small amount of polyolefin rubber of ethylene-propylene rubber or ethylene-propylene-diene rubber is added, the impact strength is greatly increased. In other words, it can be seen that the toughness is greatly improved as compared to the polyamide polymer composition to which each component resin or polyolefin-based rubber is not added.

Polyamide resin composition composed of polyamide, polyetherimide, polyolefin-based synthetic rubber in the present invention can be seen that the toughness, heat resistance, etc. is very excellent and excellent workability, electrical and electronic parts, mechanical parts, automobile / transport equipment parts, etc. It can be used as a material.

Claims (7)

A polyamide resin composition comprising 0.3 to 7 parts by weight of a polyolefin-based synthetic rubber containing ethylene-propylene as a main component with respect to 100 parts of a mixture of 40 to 90% by weight of polyamide resin and 10 to 60% by weight of polyetherimide resin. The polyamide resin composition of claim 1, wherein the polyamide resin is crystalline and has a melting temperature of 200 ° C to 270 ° C. The polyamide resin composition according to claim 1, wherein the glass transition temperature of the polyetherimide is at least 190 ° C and the ether group and the imide group are linked to the same aromatic group. The polyamide-based synthetic rubber according to claim 1, wherein the polyolefin-based rubber is polyethylene characterized by ethylene-propylene rubber or ethylene-propylene-diene synthetic rubber consisting of 3 to 30% by weight of diene comonomer and 70 to 97% by weight of ethylene and propylene. Resin composition. The polyamide resin composition according to claim 4, wherein the ethylene content of the ethylene-propylene rubber is 45 to 75% by weight. The diene comonomer of ethylene-propylene-diene synthetic rubber according to claim 4, wherein the diene comonomer comprises dicyclopentadiene, 1,4-hexadiene, ethylidenenorbornene, cyclohexadiene or propenylnorbornene group. Polyamide resin composition to be. The polyamide resin composition according to claim 1, wherein the average particle diameter of the dispersed polyamide resin or polyetherimide resin in the resin composition is 0.05 to 10 mu m.