KR100810966B1 - Composite of nylon polymer - Google Patents

Abstract

A polyamide-based resin composite material, a pellet obtained by extruding the composite material, and an interior or exterior material for automobiles or electrical/electronic products molded from the composite material are provided to improve impact resistance, fluidity and appearance characteristics. A polyamide-based resin composite material comprises 100 parts by weight of a base resin which comprises 20-80 wt% of a modified polyamide-based thermoplastic resin and 20-80 wt% of a reinforcing fiber; 1-20 parts by weight of an olefin-based impact modifier grafted with a functional group selected from maleic anhydride, glycidyl methacrylate, oxazoline and their mixture; and 0.5-15 parts by weight of an unreactive acrylate-based impact modifier.

Description

Polyamide-based resin composites {Composite of nylon polymer}

Field of invention

The present invention relates to a polyamide-based resin composite, and more particularly to a polyamide-based resin composite having excellent physical property balance in impact resistance and fluidity.

Background of the Invention

The history of polyamide resins as engineering plastics is already close to 40 years, but still in high demand. Polyamide resins are basically different types such as nylon 6, 66, 610, 612, 11, 12, and copolymers and blends thereof, and each has a useful characteristic and can produce various performances, thereby maintaining high demand. have.

In particular, by adding an inorganic reinforcing agent such as glass fiber, polyamide-based resin is greatly improved excellent mechanical stiffness and heat resistance, making it suitable for structural and automotive interior-exterior materials.

However, polyamide-based resins exhibit poor dimensional instability and warpage characteristics due to their high water absorption in the molecular structure, and also exhibit low fluidity and impact resistance when inorganic materials are added.

This low fluidity occurs because the added inorganic material interferes with the resin flow in the molten state, and the low impact resistance is low at the interface between the polyamide-based resin and the inorganic material, so that a constant impact is applied to the interface between the nylon molecule and the inorganic material. It is generally known that stress builds up and cracks are generated from the interface.

In general, rubber or the like may be added to improve the impact resistance of the composite to which the inorganic reinforcing agent is added, but there is a problem that the fluidity decreases and the mechanical properties deteriorate.

Therefore, the present inventors invented a polyamide-based resin composite having excellent physical properties in impact resistance and fluidity by adding a reactive olefin impact modifier and a non-reactive acrylate impact modifier to a base resin composed of a polyamide resin and a reinforcing fiber. It was early.

An object of the present invention is to provide a high rigid polyamide-based resin composite.

Another object of the present invention is to provide a polyamide-based resin composite having high fluidity while maintaining impact resistance.

Still another object of the present invention is to provide a polyamide-based resin composite having improved workability and appearance characteristics when forming a thin film.

Still another object of the present invention is to provide a polyamide-based resin composite material suitable for manufacturing exterior materials of automotive interior and exterior materials, high heat-resistant electronic parts, and electrical and electronic products such as computers, home appliances, and mobile phones.

The above and other objects of the present invention can be achieved by the present invention described below.

Summary of the Invention

The polyamide resin composite material according to the present invention is based on 100 parts by weight of the base resin consisting of (A) (a ₁ ) modified polyamide-based thermoplastic resin 20 to 80% by weight and (a ₂ ) 80 to 20% by weight of reinforcing fibers, (B) 1 to 20 parts by weight of the reactive olefin impact modifier and (C) 0.5 to 15 parts by weight of the non-reactive acrylate impact modifier. Hereinafter, each component of the resin composition of this invention is demonstrated in detail.

Detailed Description of the Invention

(A) Basic resin

The base resin of the polyamide-based resin composite according to the present invention comprises 20 to 80% by weight of the modified polyamide-based thermoplastic resin and 80 to 20% by weight of the reinforcing fiber.

(a ₁ ) Modified polyamide resin

The polyamide-based resin used in the present invention collectively refers to a modified nylon containing a benzene ring in the main chain.

In one embodiment of the present invention, a polyamide-based resin represented by the following general formula (1) is used.

[Formula 1]

The modified polyamide-based resin represented by Chemical Formula 1 is prepared by condensation polymerization of hexamethylene diamine and terephthalic acid, which is also referred to simply as nylon 6T.

The modified polyamide-based resin of the present invention is not limited to the above structural formula, and can be synthesized by a conventional method by applying various diamines.

The intrinsic viscosity of the modified polyamide-based thermoplastic resin used in the present invention is 0.7 to 0.9 dl / g, the number average molecular weight is 10,000 to 100,000, and the water absorption is 0.2% or less.

In general, the modified polyamide-based thermoplastic resin has a lower pyrolysis temperature than the processing temperature and thus is not easy to process. Therefore, in one embodiment of the present invention, 5 to 35 parts by weight of isophthalic acid or adipic acid is added to 100 parts by weight of the modified polyamide-based thermoplastic resin in order to lower the processing temperature below the thermal decomposition temperature. Addition and polymerization are used.

(a ₂ ) reinforcing fiber

The reinforcing fiber is used to reinforce bending properties and heat resistance. In the present invention, the reinforcing fibers are used to select one or more of glass fibers, carbon fibers, aramid fibers, kalitan titanate fibers, silicon carbide fibers, of which glass fibers are most preferred.

The reinforcing fiber may be general glass fiber having a circular cross section or specially manufactured to take the form of a plate, and a length of 2 to 13 mm may be used.

In one embodiment of the present invention, a cross section having an aspect ratio of 1.5 or more is used. In this case, the transverse-vertical ratio of the cross section of the plate-shaped glass fiber is defined as the ratio of the longest diameter (a) and the smallest diameter (length, b) in the cross section of the glass fiber as follows. When the glass fiber having a width and length ratio of 1.5 or more is used, mechanical stiffness and impact resistance are further improved.

In another embodiment of the present invention it may also be used that the aspect ratio is less than 1.5. When glass fibers having a width and aspect ratio of less than 1.5 are used, the mechanical rigidity and impact resistance are inferior, but fluidity can be improved. As for the said aspect ratio, 2-8 are more preferable.

In another embodiment of the present invention, the aspect ratio of the aspect ratio is 1.5 or more can be used in combination with less than 1.5.

The surface of the reinforcing fiber is preferably surface-treated with a surface improver to increase the surface bonding force with the polyamide-based thermoplastic resin.

In one embodiment of the present invention, urethane or epoxy is used as the surface improving agent, and the surface treatment method can be easily carried out by those skilled in the art.

In addition, the water absorption of the reinforcing fibers used in the present invention is preferably used less than 0.05%.

In the present invention, the basic resin is preferably 20 to 80% by weight of the modified polyamide-based thermoplastic resin and 80 to 20% by weight of the reinforcing fiber in consideration of mechanical rigidity and production process aspects.

(B) reactive olefinic impact modifier

The polyamide-based resin composite according to the present invention can improve impact resistance by using a reactive impact modifier that can react with the polyamide resin.

The reactive olefin copolymer is maleic anhydride in a rubber selected from the group consisting of ethylene / propylene rubber, isoprene rubber, ethylene / octene rubber, ethylene-propylene-diene terpolymer (EPDM) and mixtures thereof. Glycidyl methacrylate (Glycidylmethacrylate), oxazoline (Oxazoline) can be prepared by grafting a functional group selected in the mixture thereof. The method for grafting a reactive functional group to the olefin copolymer can be easily carried out by those skilled in the art.

The functional group is used at 0.1 to 5% by weight based on the total reactants.

(C) non-reactive acrylate impact modifier

In the present invention, the non-reactive impact modifier is to maintain a good physical property balance by reducing the decrease in fluidity.

The non-reactive impact modifier may be prepared by curing with a curing agent in the acrylate rubber, the curing method can be easily carried out by those skilled in the art to which the present invention belongs.

As the acrylate rubber, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, etc. may be used. These may be used alone or in combination of two or more thereof.

The curing agent may be ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate or 1,4-butylene glycol dimethacrylate, allyl methacrylate, triallyl. Anurate and the like can be used. These may be used alone or in combination of two or more.

In the present invention, by applying the reactive impact modifier and the non-reactive impact modifier together, the balance of impact resistance and fluidity can exhibit excellent results.

In the present invention, the impact modifier comprises 1 to 20 parts by weight of a reactive olefin impact modifier and 0.5 to 15 parts by weight of a non-reactive acrylate impact modifier with respect to 100 parts by weight of the base resin, the side and fluidity of the impact modifier, It is preferable considering other mechanical properties.

Furthermore, to the polyamide-based resin composite according to the present invention, additives consisting of antioxidants, heat stabilizers, light stabilizers, flow enhancers, lubricants, antibacterial agents, mold release agents, nucleating agents, and mixtures thereof are added within a range that does not impair the basic properties thereof. It may be.

The polyamide-based resin composite of the present invention can be produced by a known method for producing a resin composition. For example, the components of the present invention and other additives may be mixed simultaneously, then melt extruded in an extruder and prepared in pellet form.

The composition of the present invention can be used in the molding of various products, and is applied to interior and exterior materials of automobiles and electrical and electronic products. In particular, it is suitable for the manufacture of automotive interior and exterior materials, high heat-resistant electronic component materials and electrical and electronic products such as computers, home appliances, mobile phones.

Hereinafter, the polyamide-based resin composite according to the embodiments of the present invention will be described with reference to specific examples and comparative examples that are excellent in flexural strength, flexural modulus, impact strength, and fluidity.

The invention can be better understood by the following examples, which are intended to illustrate the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example and (A) used in the comparative example (a ₁₎ modified polyamide-series resin and (a ₂₎ a base resin consisting of the reinforcing fibers, (B) a reactive olefinic impact modifier and (C) non-reactive acrylate-based impact Specific component specifications of the adjuvant are as follows:

(A) Basic resin

(a ₁ ) Modified polyamide resin

HTN-501, a high heat resistant nylon manufactured by Dupont, was used.

(a ₂ ) Glass fiber with 4 aspect ratios in section

Nitto Boseki's CSG-820 was used.

(a ₂ ') Glass fiber with aspect ratio of 1 in cross section

Vetrotex P952 with a length of 3 mm and a diameter of 13 µm in cross section was used.

(B) Reactive olefin impact modifier

An olefinic impact modifier, Dupont's Fusabond MN-493D, was used.

(C) non-reactive acrylate impact modifier

Dupont Elvaloy 34035EAC was used.

Examples 1-4 and Comparative Examples 1-6

The components shown above were added to the contents shown in Table 1 below, and the pellets were prepared by extruding at a temperature range of 300 to 350 ° C. in a conventional twin screw extruder, and then injected under conditions of 300 to 320 ° C. to test the physical properties. Prepared.

Physical properties of the specimens prepared by the above Examples and Comparative Examples were evaluated according to the following methods.

(1) Flexural strength: measured in accordance with ASTM D-790, the unit is kgf / ㎠.

(2) Flexural modulus: measured according to ASTM D-790, the unit is kgf / ㎠.

(3) Izod impact strength: According to ASTM D-256, the impact strength of notched and unnotched specimens was measured at 25 ° C by using Izod method using 1/8 inch thick specimens in accordance with ASTM D-256. The unit of measurement is kgf · cm / cm.

(4) Melt Index: According to ASTM D-1238, measurement was carried out at a load of 2.16kg at 330 ° C. The unit of measurement is g / 10min.

Table 1 is a table showing the results of measuring the content ratio and flexural strength, flexural modulus, IZOD impact strength, fluidity of the impact modifier for the above embodiments and comparative examples.

Referring to Table 1 above, when the reactive impact modifier and the non-reactive impact modifier are used together as in Example, the balance of mechanical stiffness, impact resistance, and fluidity is better than that of the comparative example.

In Table 1, as the content of the reinforcing fiber is increased, the mechanical stiffness and impact resistance are increased, and the impact resistance is increased by the addition of the impact modifier, but the flexural modulus is decreased. These results show a tendency not to be related to the difference in aspect ratio of the cross section of the reinforcing fiber, but Example 1 using the reinforcing fiber having a wide aspect ratio of 4 is generally better in mechanical stiffness and impact resistance than Example 2 The results are shown. In particular, in the examples and comparative examples, the use of a reactive impact modifier capable of reacting with nylon shows a large increase in impact resistance, and the non-reactive impact modifier shows a small decrease in fluidity.

In addition, when the impact modifier was not used as in Comparative Examples 5 to 6, excellent results were obtained in flexural strength, flexural modulus and fluidity, but the impact strength was very low.

In contrast, Examples 1 and 2, which use a reactive impact modifier effective for increasing impact resistance and a non-reactive impact modifier with a small decrease in fluidity, showed the best balance of physical properties in fluidity and impact resistance.

The present invention has the effect of providing a polyamide-based resin composite having improved workability and appearance characteristics when forming a thin film by having high fluidity while maintaining impact resistance.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (16)

(A) (a ₁ ) 100 parts by weight of the base resin consisting of 20 to 80% by weight of the modified polyamide-based thermoplastic resin and (a ₂ ) 80 to 20% by weight of the reinforcing fiber; (B) 1 to 20 parts by weight of an olefinic impact modifier with a functional group selected from maleic anhydride, glycidylmethacrylate, oxazoline, and mixtures thereof; And (C) 0.5 to 15 parts by weight of the non-reactive acrylate impact modifier; Polyamide-based resin composite excellent in impact resistance and fluidity, characterized in that comprises a. The polyamide-based resin composite according to claim 1, wherein the modified polyamide-based thermoplastic resin contains a benzene ring in a main chain. The polyamide-based resin composite having excellent impact resistance and fluidity according to claim 2, wherein the modified polyamide-based thermoplastic resin is represented by the following Chemical Formula 1. [Formula 1]

. The polyamide-based resin composite according to claim 1, wherein the modified polyamide-based thermoplastic resin is polymerized by adding 5 to 35 parts by weight of isophthalic acid or adipic acid based on 100 parts by weight of the modified polyamide-based resin. The polyamide-based resin composite according to claim 1, wherein the reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, kallitan titanate fibers, and silicon carbide fibers. The polyamide-based resin composite according to claim 1, wherein the reinforcing fibers have a width and aspect ratio of 1.5 or more. The method of claim 1, wherein the modified polyamide-based thermoplastic resin has an intrinsic viscosity of 0.7 to 0.9 dl / g, number average molecular weight of 10,000 to 100,000, characterized in that the length of the reinforcing fiber is in the range of 2 to 13 mm Polyamide-Based Resin Composites. The polyamide-based resin composite according to claim 1, wherein the reinforcing fibers are surface treated with a surface improving agent. The polyamide-based resin composite according to claim 8, wherein the surface improving agent is urethane or epoxy. The method of claim 1, wherein the reactive olefin impact modifier is anhydrous to a rubber selected from the group consisting of ethylene / propylene rubber, isoprene rubber, ethylene / octene rubber, ethylene-propylene-diene terpolymer (EPDM) and mixtures thereof. Maleic anhydride, glycidyl methacrylate (Glycidylmethacrylate), oxazoline (Oxazoline) and a polyamide-based resin composite, characterized in that the copolymer grafted a functional group selected from the group consisting of. The polyamide-based resin composite according to claim 10, wherein the functional group is 0.1 to 5% by weight based on the total reactants. The method of claim 1, wherein the non-reactive acrylate impact modifier is ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate or 1,4- in the acrylate rubber A polyamide-based resin composite material cured using a curing agent selected from the group consisting of butylene glycol dimethacrylate, allyl methacrylate, triallyl cyanurate, and mixtures thereof. The method of claim 12, wherein the acrylate rubber is methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, 2-ethylhexyl methacryl A polyamide-based resin composite, characterized in that it is selected from the group consisting of a rate and a mixture thereof. The polyamide-based resin composite according to claim 1, further comprising an additive selected from the group consisting of antioxidants, heat stabilizers, light stabilizers, flow enhancers, lubricants, antibacterial agents, mold release agents, nucleating agents, and mixtures thereof. The pellet which extruded the polyamide-type resin composite material in any one of Claims 1-14. An interior-exterior material for automobiles or electric and electronic products molded from the polyamide-based resin composite according to any one of claims 1 to 14.