KR100876199B1 - Nylon/reinforced fiber composition - Google Patents

Abstract

A nylon/reinforcing fiber composition is provided to prevent bending, to improve impact resistance and fluidity, and to obtain uniform surface in case of a molded product is prepared by injection molding. A nylon/reinforcing fiber composition comprises 25-75 parts by weight of a modified nylon-based resin; 25-75 parts by weight of a reinforcing fiber having a cross-section aspect ratio of 1.5 or more; and a nonreactive impact modifier which is an olefin-based copolymer containing a nonreactive metal, wherein the content of the nonreactive impact modifier is 1-10 parts by weight based on 100 parts by weight of the modified nylon-based resin and the reinforcing fiber. Preferably the modified nylon-based resin is represented by the formula 1, wherein n is 50-500.

Description

Nylon / Reinforced Fiber Compositions {NYLON / REINFORCED FIBER COMPOSITION}

The present invention relates to a nylon / reinforcing fiber composition, more specifically, a nylon / reinforcing fiber that can be produced injection molding having no warpage phenomenon, excellent impact resistance, improved fluidity, and a uniform surface It relates to a composition.

Nylon-based resin is a representative engineering plastic, widely used as interior and exterior materials of automobiles. However, nylon-based resins have problems such as dimensional instability and warpage due to high water absorption, so that an inorganic reinforcing agent such as glass fiber is added to improve the structural properties and automobiles that require excellent mechanical rigidity and heat resistance. It is widely used in interior and exterior materials.

However, the impact resistance is lowered as the inorganic reinforcing agent is added. Recently, a modified nylon having a benzene ring in the main chain is used to improve the high water absorption of the existing nylon, and further, the impact reinforcing agent is used to further improve the nylon and the inorganic reinforcing agent. Attempts have been made to improve the impact resistance of the mixtures. However, even when modified nylon is used, the effect of improving water absorption is insignificant, resulting in dimensional instability and warpage problems, and the use of impact modifiers to improve impact resistance lowers mechanical rigidity and lowers fluidity. The manufacturing of the molded article by the injection process with the fiber composition did not overcome the limitation of the non-uniform surface.

It is an object of the present invention to provide a nylon / reinforcement fiber composition which is excellent in impact resistance and fluidity, and which can produce an injection molded product having a uniform surface when forming a molded article by injection molding .

The present invention also aims to provide a molded article made of the composition.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

One embodiment of the present invention (A) 25 to 75 parts by weight of modified nylon-based resin; (B) 25 to 75 parts by weight of reinforcing fibers having a cross-sectional aspect ratio of 1.5 or more and a non-reactive impact modifier, wherein the content of the non-reactive impact modifier is 1 to 10 parts by weight based on 100 parts by weight of the mixture of the modified nylon resin and the reinforcing fibers. It is to provide a nylon / reinforcing fiber composition in parts by weight.

Another embodiment of the present invention is also to provide a molded article prepared using the composition.

Other specific details of embodiments of the present invention are included in the following detailed description.

The nylon / reinforced fiber composition of the present invention is free from warpage, has excellent impact resistance and fluidity, and can produce a molded article having a uniform surface.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

One embodiment of the invention relates to a nylon / reinforcement fiber composition. In particular, the resin composition of the present invention relates to a nylon / reinforced fiber resin composition which is free from warpage and can solve the problem of lowering fluidity when improving impact resistance in the related art, that is, excellent in both impact resistance and fluidity. Since the resin composition of the present invention is excellent in fluidity, a molded article having a uniform surface may be manufactured when the molded article is manufactured using the resin composition.

In the present invention, it was possible to improve the fluidity while maintaining the mechanical properties by using a non-reactive impact modifier, and the warpage phenomenon can be improved by using a glass fiber of the plate shape having a cross-sectional aspect ratio of 1.5 or more.

Hereinafter, each component will be described in more detail.

(A) modified nylon resin

The modified nylon resin used in the present invention has a low water absorption rate and excellent rigidity. The modified nylon-based resin preferably has an intrinsic viscosity of 0.7 to 0.9 dl / g.

Modified nylon-based resin of the present invention is a high heat-resistant modified nylon resin containing a benzene ring in the main chain, represented by the formula (1) prepared by condensation polymerization with hexamethylene diamine and terephthalic acid as a representative example Nylon 6T.

[Formula 1]

(In Formula 1, n is 50 to 500)

In the present invention, the modified nylon resin may be prepared by condensation reaction between hexamethylene diamine and terephthalic acid, or may be commercially available.

In addition, the modified nylon resin of the present invention further comprises isophthalic acid, adipic acid or a mixture thereof in an amount of 5 to 35 parts by weight based on 100 parts by weight of the total resin to improve processability. You may. When isophthalic acid, adipic acid or a mixture thereof is included in the above range, the processing temperature can be lowered while maintaining an appropriate heat distortion temperature.

The modified nylon resin of the present invention preferably has a water absorption of 0.1% by weight or less. When the water absorption of the modified nylon resin exceeds 0.1% by weight, workability is lowered, which is not preferable.

In the nylon / reinforcement fiber composition of the present invention, the content of the modified nylon resin is preferably 25 to 75 parts by weight, more preferably 40 to 60 parts by weight .

When the content of the modified nylon-based resin is included in the 25 to 75 parts by weight, the production process is stable, it is preferable because the mechanical rigidity is excellent.

(B) reinforcing fiber

The reinforcing fibers used in the present invention preferably have an aspect ratio obtained by dividing the long axis length of the fiber cross section by the short axis length, and more preferably 2 to 8 .

As examples of the reinforcing fibers in the present invention, glass fibers, carbon fibers, aramid fibers, Kita Titan (K ₂ TiO ₃ ) fibers , silicon carbide fibers or mixtures thereof may be used.

In addition, the reinforcing fibers have a length of 2 to 13 mm, and plate reinforcing fibers are used.

The plate-shaped reinforcing fibers have an aspect ratio of 1.5 or more in cross section, wherein the aspect ratio of the cross section is a longest diameter in the cross section of the reinforcing fiber a, the smallest diameter (vertical) ) Is defined as a / b. The aspect ratio of the cross section is 2 to 8 is more preferable in terms of the balance of physical properties of mechanical properties and bending properties.

As the reinforcing fiber, it is more preferable to use a surface improving agent coated on the surface in order to increase the bonding strength with the modified nylon-based resin. Urethane or an epoxy resin is mentioned as this surface improving agent. Surface coating process can be applied to any general coating process such as dip coating, spray coating.

In the nylon / reinforcement fiber composition of the present invention, the content of the reinforcing fiber is preferably 25 to 75 parts by weight, more preferably 40 to 60 parts by weight .

  If the content of the reinforcing fiber is in the range of 25 to 75 parts by weight, it is preferable because it is excellent in mechanical rigidity and the production process becomes stable.

(C) non-reactive impact modifiers

As the non-reactive impact modifier of the present invention, an olefin copolymer containing a non-reactive metal may be used. The olefin copolymer containing the said non-reactive metal can mention the olefin copolymer which has a non-reactive metal at the terminal.

The olefin copolymer is selected from the group consisting of ethylene / propylene rubber, isoprene rubber, ethylene / octene rubber, ethylene-propylene-diene terpolymer (EPDM), ethylene-methacrylic acid (EMAA), and mixtures thereof. Can be used.

As the non-reactive metal, zinc (Zn), iron (Fe) or manganese (Mn) may be used. The non-reactive metal may be used in combination, and zinc (Zn) is more preferable.

Conventional reactive olefinic impact modifiers are those obtained by reacting a reactive compound such as maleic anhydride, but such reactive impact modifiers have reduced impact strength and flow properties, and thus, in the present invention, non-reactive impact modifiers are used. It is preferable in terms of the balance of physical properties of impact strength, fluidity and flexural strength.

Since the method for preparing the olefin-based copolymer including the non-reactive metal may be easily carried out by those skilled in the art, detailed descriptions thereof will be omitted. In the present invention, as the non-reactive impact modifier, an olefin copolymer containing a non-reactive metal may be prepared and used, or a commercially available one may be used.

The content of the non-reactive impact modifier in the nylon / reinforcement fiber composition of the present invention is preferably 1 to 10 parts by weight, more preferably 3 to 7 parts by weight based on 100 parts by weight of the modified nylon-based resin and the reinforcing fiber mixture. When the content of the non-reactive impact modifier is in the range of 1 to 10 parts by weight, the effect of sufficient impact reinforcement can be obtained, excellent fluidity and mechanical properties, and do not cause peeling problems during injection molding.

The nylon / reinforcement fiber composition of the present invention adds general additives such as pigments, antioxidants, heat stabilizers, light stabilizers, flow enhancers, lubricants, antibacterial agents, mold release agents, and nucleating agents within the range of not impairing the physical properties other than the above components. It may be included as, the amount may be used in 30 parts by weight or less based on 100 parts by weight of the modified nylon-based resin and reinforcing fibers.

Another embodiment of the present invention relates to a molded article manufactured using the nylon / reinforcing fiber composition, the molded article can be used in a variety of products, particularly useful for structural or automotive interior and exterior materials that require excellent mechanical strength and heat resistance Can be applied.

The following presents specific embodiments of the present invention. However, the embodiments described below are merely for illustrating or explaining the present invention in detail, and thus the present invention is not limited thereto.

Example

 The specifications of each component used in the following Examples and Comparative Examples are as follows.

(A) modified nylon resin

Polyphthalamide (Dupont's HTN-501), a modified nylon resin having a benzene ring in the main chain, was used.

 (B) reinforcing fiber

The aspect ratio of the fiber cross section was 4, and glass fiber (CSG 3PA-820 from Nitto Boseki, Japan) was used.

(C) non-reactive impact modifiers

Dupont Surlyn 9020 with Zn non-reactive metals was used.

(C-1) Reactive Impact Enhancer

Fusabond MN-493D olefin impact modifier from Dupont was used.

Example 1-2 and Comparative Example 1-3

The components are mixed according to the content (unit: parts by weight) shown in Table 1 below, and fixed at 250 ° C. (example) and 320 ° C. (comparative example) using a twin screw extruder having L / D = 45 and Φ = 45 mm. The pellet was produced by extrusion under the conditions of temperature, screw rotation speed of 150 rpm and self feed rate of 60 kg / hr. The prepared pellets were dried at 100 ° C. for 4 hours, and then injected under conditions of an injection temperature of 3300 ° C. in a 10 oz injection machine to prepare specimens for evaluation of physical properties, and the physical properties thereof were shown in Table 1 below .

Example Comparative example One 2 One 2 3 Composition (parts by weight) (A) modified nylon resin 50 50 50 50 50 (B) reinforcing fibers with an aspect ratio of 4 in cross section 50 50 50 50 50 (C) non-reactive impact modifiers 3 5 - - - (C-1) reactive impact modifier - - One 3 5 Properties ① Flexural Strength (kgf / cm ² ) ASTM D790 3200 2900 300 2800 2500 ② Flexural modulus (kgf / cm ² ) ASTM D790 150,000 140,000 160,000 130,000 120,000 ③ Izod impact strength (kgfcm / cm) Notched ASTM D256 13 16 13 14 14 Un-notched 107 120 70 106 110 ④ Flow index (MI) (g / min) ASTM D1238 25 20 30 12 7

* Property measurement method

Specimens prepared by the Examples and Comparative Examples were measured after leaving for 48 hours at 23 ℃, 50% relative humidity in accordance with ASTM D3641.

(1) flexural strength

Flexural strength is horizontal x vertical x thick = 127 x 12.7 x 6.4 (unit: mm) according to ASTM D790 Measured using a specimen with size, the unit is kgf / cm ² .

(2) Flexural modulus

Flexural modulus was measured in width x length x width = 127 x 12.7 x 6.4 (unit: mm) according to ASTM D790, and the unit is kgf / cm ² .

 (3) Izod impact strength

Notched specimens were measured using 1/8 inch thick specimens according to ASTM D256, and un-notched specimens were also measured in the same manner as above.

(4) Flow index (MI: Melt index, also called Melt Flow Index)

The flow index was measured according to ASTM D1238 and the unit is g / 10 min.

As shown in the results of Table 1, the resin composition of Examples 1 to 2 has no physical property deterioration and excellent flow characteristics compared to Comparative Examples 1 to 3. In addition, when comparing Example 1 and Comparative Example 2 with the same content of the impact modifier, Example 1 using a non-reactive impact modifier compared to Comparative Example 2 using a reactive impact modifier, while maintaining the flexural strength and flexural modulus, It shows excellent results that are remarkably improved.

The present invention is not limited to the above embodiments, but may be manufactured in various forms, and a person skilled in the art to which the present invention pertains has another specific form without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (7)

(A) 25 to 75 parts by weight of the modified nylon resin; (B) 25 to 75 parts by weight of reinforcing fibers having a cross-sectional aspect ratio of at least 1.5; (C) a non-reactive impact modifier which is an olefin copolymer containing a non-reactive metal It includes, the content of the impact modifier is 1 to 10 parts by weight based on 100 parts by weight of the modified nylon-based resin and reinforcing fiber mixture Nylon / Reinforcement Fiber Compositions. The method of claim 1, The modified nylon resin is a nylon / reinforcing fiber composition represented by the following formula (1). [Formula 1]

(In Formula 1, n is 50 to 500) The method of claim 1, The reinforcing fiber is a nylon / reinforcing fiber composition in the form of a plate. The method of claim 1, Wherein said reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, kallitan titanate fibers, silicon carbide fibers, and mixtures thereof. delete The method of claim 1, The non-reactive metal is selected from the group consisting of zinc (Zn), iron (Fe), manganese (Mn) and combinations thereof, The olefin copolymer is selected from the group consisting of ethylene / propylene rubber, isoprene rubber, ethylene / octene rubber, ethylene-propylene-diene terpolymer (EPDM), ethylene-methacrylic acid copolymer (EMAA), and mixtures thereof. Nylon / reinforcement fiber composition. The method of claim 1, The nylon / reinforced fiber composite composition further comprises an additive selected from the group consisting of pigments, antioxidants, heat stabilizers, light stabilizers, flow enhancers, lubricants, antibacterial agents, mold release agents, nucleating agents, and mixtures thereof. Composition.